Most sounds in music have a pitch. Scientifically speaking, "pitch" is a measure of the frequency of a noise. Quick physics lesson: every noise is just vibrations in the air around us. The number of vibrations per second (as measured in hertz) determines the frequency. This is physics, and it's not very interesting, so we won't spend much time on it.

Pitches are also understood using the alphabet system of A-B-C-D-E-F-G. Back when this system was devised, it was for Gregorian chant, and "A" was simply "the lowest pitch we're going to sing for this song." As such, the exact frequency of "A" was completely arbitrary, depending on which Gregorian monks you happened to have with you right now. Eventually, with the invention of the tuning fork in 1771, it became possible to standardize the frequency of various pitches. Today, the official "home base" of music is A440, so called because the frequency of said pitch is 440 hz and it is used as an A. Most instruments and tuning forks are tuned directly according to this pitch (except for the ones that aren't,or sometimes aren't).

Obviously, there are a lot of available frequencies between 0 and 440, and more beyond it. You'll be glad to know that the larger majority of them aren't used. Western notation tends to stick with 88 of them — coincidentally, the 88 heard when you press the keys on a piano. There are a number of ways to notate them, but we're going to stick with a combination of "scientific pitch notation," which actually names them after the piano keys — the lowest being A0 and the highest being C8, and the numbers incrementing every time you have a new C — and "hertz" notation, where a pitch is listed with its hertz quantity — A440, for instance. For the heck of it, we'll use both. At this time we should take a moment to mention that the "scientific pitch notation" name for A440 is A4, so-called because it's the 4th "A" key on a piano (not counting the A0 way down at the bottom; remember, the incrementation occurs at C).

Scales

Scales are series of pitches that feel like they go together. The most normal-sounding scale for most human beings is the "major" scale. The pitches in a scale have very specific mathematical relationships to one another, but again we're not going to bother getting into that.

Pitches are also classified in "half-steps," which is the true indivisible interval in Western notation. The closest two pitches can be together is a half-step, which typically involves a sharp (♯) or flat (♭) sign. For instance, you can have the pitches A and B, and they're directly next to each other as white keys on the piano... but they have a black key in between them. This black key represents the half-step, and is either called A♯ or B♭ depending on the circumstances (There are rules about this that we will get into later). The distance between the two white keys, if they have a black key between them, is called a whole step. These terms are used frequently when describing intervals.

"But what about if there's two white keys without a black key in between them?" you might be asking if you've glanced at a piano recently. Congratulations! You've found a half-step! Now let us help you make sense of why a black key should not be there.

The major scale is composed of specific intervals: A pitch, another pitch a whole step above that, another pitch a whole step above that, a pitch that's a half-step above the third one, three more pitches that are ascending whole steps, and one more half-step pitch that brings us back around. See, the reason that the letters in Western music are only A through G is because the thing above G is another A. So if you had an A major scale starting at A4 / A440, the top of the scale would be A5 / A880. (Pitches double in hertz value when they go up or down this way.) The distance between A4 and A5 is called an "octave," so called because it takes eight steps to go from A4 to A5.

Though A4 / A440 is the benchmark against which all instruments are tuned, there is also a second benchmark that is used frequently. It's C4 / C261.63, the C below A440. It's called "Middle C", because it's the one note that basically any pitched instrument can hit, and the one note that basically every human being can sing. (People who play piano and other keyboarded instruments also like C because as mentioned, the C major scale is the only major scale that can be played using all white keys. Every other scale requires at least one black key.)

Speaking of scales: as mentioned, there are 11 half-steps in an octave. All of them can have scales built upon them. You can have G♯ major. You probably won't, though; you'll probably call it A♭ major. ^note  Although if you are a guitar player playing barre chords, you might. There are rules about this that we will get into la... Actually, let's just get into them now: The key you are playing in, the scale you are using, is determined by a graphic called a "key signature." It's a visual guide that says, "Replace these white keys with the next black key over." (It also means the score doesn't need to notate every single fundamental sharp or flat in the scale, making it more legible.) The key signature will have sharps if you're supposed to play the next black key up, and flats if you're supposed to play the next black key down. (It will never have both.) This is why the black key between A and B is called either A♯ or B♭: its name is different depending on which key you're in. Now, because there are seven white keys, the key signature can never have more than seven sharps or flats. The reason you'll never have G♯ major is because playing it requires eight sharps: G♯, A♯, B♯, C♯, D♯, E♯ and F double-sharp. Now, you could write it that way... but there also exists the key of A♭ major, which only has 4 flats and uses the exact same combination of black and white keys that G♯maj does. It may be called something different, but it sounds exactly the same, at least in terms of pitches. Every possible key (all 12 of them) can be described with a key signature; if you take a look at the "Circle of Fifths" folder, you'll see that a couple, like B major, actually have more than one common description (it can also be called "C♭major," 7 flats, instead of 5 sharps). Perhaps for this reason, there is a third pitch-description system that assigns every key on the piano a unique number, but we're not going to bother with it because two is enough to start with.

Now, a couple of you readers may be wondering: "But wait. I've heard musicians referring to double-sharps and double-flats before. Don't those actually exist?" And the answer is, yes, they do. There is a sign for double-sharp — 𝄪 — and for double-flat — 𝄫. However, these signs are not used in key signatures because, again, they aren't necessary; anything that can be expressed with double-sharps can also be expressed with single sharps or with flats. (There are some semantic differences between G♯maj and A♭maj, of course — some musicians will swear that key signatures which are represented with flats sound warmer and darker, while sharp key signatures sound brighter and colder. There is some science to this, specifically the fact that the higher a note is, the harder it is to play... but that's true the lower a note is too. By and large, the difference between G♯maj and A♭maj is subjective. Although the method of tuning an instrument uses can also affect that.)

Modes of the Major (Diatonic) Scale

(directed viewing: Charles Cornell)

As mentioned, every scale consists of the same mathematical relationships between pitches. So a question that might have occurred to you is, "What if we started the scale on a different place in the cycle?" Congratulations: you have discovered Modes, which are exactly that.

There are seven different modes of the Major/Minor scale, since there are seven different pitches you can start on in a scale:

Ordering modes by brightest to darkest: Lydian > Major > Mixolydian > Dorian > Minor > Phrygian > Locrian.

To be more precise, these are the relative modes of your key. If you keep your starting pitch the same, but alter some of the degrees, you get the parallel modes. For example, start with C Major, then these are the parallel and relative modes:

Note: If you extended this table by continuing on the Circle of Fifths, you would flatten your starting pitch by a semitone, from C to B. The result would not be a new parallel mode, but the Lydian mode a semitone lower, i.e. B Lydian, and then this cycle continues. (Likewise, if you go the other way, beyond C Lydian, you'll get C♯ Locrian next by raising C and F a semitone.) Meanwhile, if you keep doing this with relative modes, you get C Ionian again.

Modes are a neat tool to give your song more character and to dial in the vibe you are going for. Many songs will use chords from other modes but stick to Major (Ionian) or Minor (Aeolian) for the most part, but some will make much more use of the other modes:

• Lydian: Lydian is adjacent to Major (Ionian), but has the 4th raised by a semitone. This 'augmented 4th' means that Lydian has a tritone above the root tone, which only two modes of the Major scale do. This gives Lydian a very bright but also rather 'unstable' characteristic. Some examples of songs in Lydian:
  • "I Follow Rivers" by Lykke Li is in F Lydian. While the characteristic ♯4 note isn't in the vocal melody, it is worked into the song's harmony a lot.
  • "Man On The Moon" by R.E.M. has verses in Lydian.
  • Saria's Song/Lost Woods from The Legend of Zelda: Ocarina of Time.

• Mixolydian: the slightly moodier, more serious brother to Major (Ionian). Songs in Mixolydian tend to sound more 'melodic', due to how the flattened 7th can be better worked into harmonies. Examples of Mixolydian include:
  • the Star Trek theme
  • "Clocks" by Coldplay
  • "Hey Jude" by The Beatles ("naaaaa na na na-na-na-naaa" section only)
  • "Cruel World" by Lana Del Rey

• Dorian: Dorian is very similar to Minor (Aeolian), but sounds a bit brighter due to lacking the flattened 6th. Songs written in Dorian sound somber, yet hopeful compared to Minor, and often have a mystical vibe to them, similar to how Lydian compares to Major. Examples of the Dorian mode include:
  • "Scarborough Fair" (probably Covered Up to most tropers by Simon & Garfunkel)
  • "Thriller", "Smooth Criminal" and "Bad" by Michael Jackson
  • "Mad World", both the original version by Tears for Fears and the Covered Up piano version by Gary Jules
  • "Memories" by David Guetta
  • "Radioactive" by Imagine Dragons
  • "Wicked Game" by Chris Isaak
  • "Cavi Cape" from Mario & Luigi: Bowser's Inside Story

• Phrygian: sounds darker compared to Minor and often gives songs a foreign, exotic vibe. The characteristic flattened second makes Phrygian sound rather distinctive from the previous modes. Practically, Phrygian often acts like Minor but on steroids: whereas Minor sounds tragic, Phrygian has you cross the Despair Event Horizon. When Minor sounds foreboding, Phrygian sounds threatening. When it's romantic, Phrygian sounds downright sultry. Examples of songs in Phrygian:
  • Samuel Barber's Op. 11, "Adagio For Strings" (see TearJerker.Platoon); Magus's Theme from Chrono Trigger (the opening violin figure actually outlines a descending E-Phrygian scale)
  • "Wherever I May Roam" by Metallica
  • "Freak On A Leash" by Korn
  • "If U Seek Amy" by Britney Spears
  • "Only When I Lose Myself" by Depeche Mode (chorus is in Dorian, though)
  • "HUMBLE." by Kendrick Lamar
  • "Candy Shop" by 50 Cent
  • "SexyBack" by Justin Timberlake
  • "Baby Boy" by Beyoncé and Sean Paul
  • "Hunter" by Björk
  • "Smack My Bitch Up" by The Prodigy
  • "Pyramid Song" by Radiohead
  • "Set The Controls For The Heart Of The Sun" by Pink Floyd

• Locrian: Like Lydian, the Locrian mode has a tritone above the root tone. This scale has the same alterations as Phrygian as well as a flat 5th — the "tritone," the ultimate Brown Note — and as a result sounds so weird that basically everyone just avoids it. Or uses it exactly because it sounds so unpleasant. Some rare examples of the Locrian mode are:
  • "Army Of Me" by Björk is by far the most frequently cited and well-known example, even though it is debated whether the entire song sticks to C Locrian or switches to a more stable mode for the chorus
  • the Among Us 'space' theme
  • the main soundtrack during gameplay in Plague Inc. Evolved
  • "Biscuit" by Portishead
  • "Nasty" by The Prodigy
  • a hidden track following "Yummy" by Gwen Stefani which sounds like a circus band straight from Hell.
  • "Off To The Races" by Lana Del Rey uses short sections of Locrian to give this song a really eerie vibe: the pre-chorus has her (and the underlying melody's top) pitch drop by a semitone every second half of a bar, changing the mode from E minor to E Locrian. The recurring theme of abusive relationships is so obvious here that even the music is like 'something is very wrong with this'.
  • "Anything Like Me" by Poppy begins mellow in E Major before transitioning into a much heavier part in E Locrian.

Other scales and modes

Of course, the Diatonic scale is not the only way you can arrange pitches between an octave. Other common scales include:

• Harmonic Minor: take a Minor scale, for example A Minor (A–B–C–D–E–F–G–A) and raise the 7th degree (the second to last tone) by a half-step. The resulting scale (A–B–C–D–E–F–G♯–A) is called A Harmonic Minor. \\

• "...Baby One More Time" by Britney Spears
• the verses of "Paint It, Black" by The Rolling Stones
• "bury a friend" by Billie Eilish. CW: this music video has a fair share of Nightmare Fuel. Especially if you are squeamish about needles.
• "The Diner" by Billie Eilish

• Phrygian Dominant: actually a mode of the Harmonic Minor scale. If you take A Harmonic Minor and start on E, you get E Phrygian Dominant. Or, you could take a Phrygian mode, for example E Phrygian (E–F–G–A–B–C–D–E), and this time, raise the 3rd degree by a half-step. The result will also be E Phrygian Dominant (E–F–G♯–A–B–C–D–E). Phrygian Dominant has a very distinctive, "oriental" sound to it; and this scale is actually a common scale (maqam) in Arabic music, called Hijaz Kar.
  Examples of songs using the Phrygian Dominant scale include:
  • "White Rabbit" by Jefferson Airplane, switches between F♯ Phrygian Dominant and F♯ Phrygian
  • "Overload" by the Sugababes, which uses a similar riff to "White Rabbit"
  • "Come Out And Play" by The Offspring
  • "Naughty Girl" by Beyoncé
  • "Gila Monster" by King Gizzard and the Lizard Wizard

• Double Harmonic: very similar to Phrygian Dominant, but with the 7th degree also raised by a half-step. Use the same method for making a Harmonic Minor out of a Minor scale, but start with a Phrygian Dominant scale instead. It has almost identical characteristics to the aforementioned.
  Some examples of Double Harmonic include:
  • "Misirlou" by Dick Dale: one of the most iconic surf rock songs and guitar riffs of all time uses the Double Harmonic scale.
    • So does "Pump It" by The Black Eyed Peas, which samples this riff.
    • And, of course, the Greek folk song it is based on.
  • "Talk Dirty" by Jason Derulo.
  • "Hava Nagila", a traditional Jewish folk song.
    • As well as all of the innumerable Eurobeat, Trance and Gabber songs that sample it.

• Pentatonic scales are made out of five pitches, without counting the octave. (The aforementioned scales have seven and are therefore called heptatonic.) An example of a diatonic, pentatonic scale would be C–D–E–G–A–C. This particular scale features no half-steps. Pentatonic scales are ubiquitous in Eastern Asian music, but not unheard of in Western music as well. They also feature heavily in improvisation, particularly in the blues and most forms of rock music. Examples include:
  • "My Girl" by The Temptations. The intro consists of the aforementioned C–D–E–G–A–C sequence played repeatedly.
  • "Amazing Grace" by John Newton.

• Octatonic scales have one extra pitch compared to the common heptatonic scales. The most common octatonic scale is a sequence of alternating half-steps and whole tone steps and is also known as Diminished Octatonic (for the diminished fifth added to the regular fifth). This scale sounds very dark in general, and its harmonies evoke semblance to the Dorian, Phrygian, and Locrian modes. Examples of songs using this Octatonic scale include:
  • "Hey Daddy" by Korn
  • "Pursuit" by Gesaffelstein

• Another type of octatonic scales are known as Bebop scales. They are obtained taking a heptatonic scale and adding a passing note from a different mode of that scale. Bebop scales take their name from the Bebop era of jazz music. Examples include:
  • "Cradles" by Sub Urban, adding a E♮ from C♯ Dorian to the C♯ Major scale

• Blues scales contain the eponymous blue notes, notes from (usually) Minor scales added to a (usually) Major scale for a much more diverse harmony.

• A scale using all twelve half-steps in an octave would be called a chromatic scale. However, such a scale is almost never used. Melodies and Harmonies may feature notes not found in their respective key occasionally, though. Those notes are referred to as chromatic notes.

Intervals

An "interval" is the chromatic/pitch space between two notes. They are typically defined using numbers; for instance, the interval between the bottom note of a piano and its top note would be... What, a 51st? In practice, intervals rarely get into double digits, because large jumps are physically difficult to perform.

From a practical standpoint, an "interval" has its number assigned by counting how many white keys, or letters are between, are between them, counting the notes actually being played. The interval between C and an E is a third, because there are three white keys involved: the C, the D and the E. The same system is applied even if there are black keys involved; a D♯ to an F♯ is also a third, even though there are technically only two white keys — E and F — between them, because if you played them a half-step down — D natural to F natural — it would... yeah, you see where this is going. This is why it can be helpful to count note names, letters in this case, especially if you are not familiar with the keyboard.

(Just like there are signs for sharp and flat, there's one for natural: ♮. It is used most frequently as an "accidental," which is when you play a note that's a half-step different than what would be in the key normally. Despite its name, most accidentals are deliberate.)

From a technical standpoint, "intervals" are collections of half-steps, which we have already talked about. Every interval you can think of (not to mention all the ones you can't) are defined by how many half-steps they contain. That piano-spanning 51st, for instance, involves 88 half-steps. C to E involves four half-steps, so it's a third; D to F involves three half-steps, so it's... also a third? Hold on a second.

What's the difference? Do they really have the same name? Yes and no. They're both thirds... But C to E is a major third, and D to F is a minor third.

Most intervals come in major or minor flavors. One half-step, C to C♯, is a minor second; two, C to D, is a major second. We've covered thirds. You can also have major or minor sixths (8 half-steps vs. 9) and sevenths (10 half-steps vs. 11). More importantly, though, there are a few intervals that don't come in major or minor variants. Instead, there's only one of that interval, and they are called "perfect." These are the perfect fourth (5 half-steps), the perfect fifth (7 half-steps) and the octave (12 half-steps).

We can also define intervals larger than the octave. In this case, we subtract an octave – 12 semitones – from the number of semitones and add the remaining interval. For example, a "minor ninth" (13 semitones) is equal to an octave plus a minor second, and so on. This can, in theory, be extended indefinitely. However, ninths, elevenths and thirteenths are rarely mentioned outside of jazz theory, and even larger intervals are hardly ever mentioned at all.

Sharp-eyed readers have probably noticed that there's a quantity of half-steps that has been skipped: six of them. There's a reason for this: six half-steps, exactly half an octave, is called a "tritone" (because it's three whole steps)... and, for whatever reason, it sounds really bad; for proof, look no further than the memetic, Creepypasta-inspiring "Lavender Town" theme from Pokémon Red and Blue (the signature ostinato goes C-G-B-F♯, forming a tritone with the first and last notes). The tritone has been called "el diablo in musica" (the Devil in music) and it is so dissonant that Common Knowledge maintains that its use was allegedly banned by the Vatican for many years. ^note Common knowledge as in people think it is true, but it is not. This is not to say that it cannot be used well and artistically; like the aforementioned Lavender Town theme, many other works feature a prominent tritone:

• the opening titles of The Simpsons uses it (from "The" to "Simp-")
• the eponymous figure in "Maria" from West Side Story
• Johannes Brahms adds them to the fourth movement of his Ein Deutches Requiem and makes them heartbreakingly beautiful.
• even the Nintendo Wii makes use of it: the very first of the famed "doot doot doots" from the Mii Channel Theme, in the second measure of the song, are a tritone chordioid, both notes of the interval played simultaneously.

Rules are made to be broken, and it's absolutely possible to make tritones work. But it's challenging in most genres. However Heavy Metal has used it as part of its mythos, even when tritones were not actually being used.

Depeding on context, the tritone may also be referred to as a "diminished fifth" (e.g. C–G♭) or an "augmented fourth" (e.g. C–F♯). This nomenclature can also apply when working in scales which have intervals larger than a major second between them. For example, in a Phrygian Dominant scale built on E (E-F-G♯-A-B-C-D-E), the pitches F and G♯ are said to be an augmented second apart instead of a minor third, to avoid confusion with the major third between F and A. Generally, an "augmented" interval is one semitone larger than the corresponding perfect or major interval and a "diminished" interval is one semitone smaller than the corresponding perfect or minor interval. These terms are not stacked with each other because they would produce even more redundant terms. I.e., a "diminished major third" would just be a minor third, and "augmented diminished fourth" would cancel out to "fourth".

Finally, let's talk a little bit about inverted intervals. Let's say you play a C4 / C261.63, a C5 / C523.251, and an A4 / A440. What intervals do you have? Obviously, there's an octave (12 half-steps) between the two C's, and therefore a major 6th (9 half-steps) between the C4 and the A4... and, therefore, a minor 3rd (3 half-steps) between the A4 and the C5. Every interval has a flipside this way: minor 2nds to major 7ths, major 2nds to minor 7ths, minor 3rds to major 6ths, and even perfect 4ths, which are the flipside of the perfect 5th. The exceptions are the tritone, which is its own inversion, and the octave, the flipside of which is two notes with the same pitch, (also called a unison), which typically just means one note. ^note On some instruments it is possible to play the same note in two places at the same time. Trying to invert an octave is the musical equivalent of trying to Divide by Zero.

Rhythm

As you may have started to notice, there's a lot of recursivity in music. There are very few discrete concepts that can be defined using normal, natural, real-world explanations; most of it requires a context of other concepts that you then have to learn before the original concept makes sense. Rhythm is no different, so hold on to your asses.

Rhythm, in music, is determined in three ways: meter, tempo and duration.

Meter

In a time signature, the number on the bottom (what's called a denominator in fractions) tells you what kind of note to look for in defining the measure. The top number (the numerator) tells you how many of those notes to look for. Now, note durations in music are always created by dividing by two, so the bottom number will always be a power of 2. The top number, though, could be anything.

The most popular time signature is 4/4, or "common time" (to the point it is sometimes just notated as a capital "C"). The bottom number tells us that we should be looking for notes that are equal to 1/4 of a whole — for instance, a quarter note. The top number tells us that four of these "quarter notes" comprise a measure. A better way of describing it might be to say that the top number tells you what number to count to before the measure is over. In 4/4 time, after you've counted to 4, you get a new measure. The bottom number, on the other hand, tells you what duration to ascribe to each count.

Yes, we are aware that 4/4, as a fraction, can be reduced to the integer 1. You should not do this. The reason for this is actually the way bars are subdivided into beats, and how those are subdivided into eighth notes:

• A 4 at the bottom means the meter is oriented on subdivisions of two eighth notes.
• A 8 at the bottom means the meter is either oriented on subdivisions of three eighth notes or mixes both aforementioned subdivisions.
• A 2 at the bottom is generally only seen in classical music and marches, and indicates a faster, "cut" time, i.e. no subdivisions.
• Finer subdivisions are also possible, but they are very uncommon outside of experimental and avant-garde music. Really freaky time signatures may also have a 16, 32, even a 64 at the bottom.^note Rhythms subdivided into 64th notes are already extremely difficult to play, and 128th and above become are basically impossible to play back as a human, or must be played back at such slow tempos that a notation in a less fine subdivision makes more sense by keeping things from getting too convoluted. As always, make things only as complicated as necessary. Sure, you could fit an entire song into something like one 4096/128 bar, but such a notation is of no use.

For example, 4/4 generally has 4 beats with two eighth notes each:

If "4/4" is the most popular time signature, this implies that there are others that aren't as popular. For instance, there's 2/2, "cut time," (like common time, it is sometimes notated with a "C", except there's a line through it like the U.S. cent symbol "¢") which is typically used for marches:

There's also 3/4, which is often called a Waltz, from the German dance Walzer which is always in this time signature:

• Example: "Unwanted" by Avril Lavigne.^{Avril wrote waltzes?}No, just a rather heavy song in 3/4. I mean, no one's stopping you from waltzing to it... but it may not quite fit the lyrics.

Then there's 6/8, which is made up of two beats subdivided into three. It looks like it is used for really weird marches for aliens with three legs, but may also be used to avoid writing lots of triplets, instead playing at 1.5x tempo:

• Example: House of the Rising Sun by The Animals.

3/4 and 6/8 look like they should sound the same (and mathematically, they are the same length: six eighth notes), but they don't, because #/8 in music is code for "Each subdivision is actually a count of three instead of two; each individual beat sounds like a waltz in and of itself."

Following this logic, 9/8 is somewhat of a waltz-ception by having 3 beats which subdivide into 3 again:

• Examples: "Rocky Road to Dublin", a traditional Irish "slip jig" song, and "imagine" by Ariana Grande (more specifically the verses).

Likewise, if you want 4/4 but with each beat subdivided into three, you get 12/8:

• Example: "The Sweet Escape" by Gwen Stefani.

And then we can start mixing both of these beats to get time signatures where you can't even count symmetrically. Meters that aren't Common Time or cut time actually have their own page here: Uncommon Time.

For example, 5/8 may look like this:

• Example: the intro of "Polygondwanaland" by King Gizzard and the Lizard Wizard.

You may also play each beat twice, respectively; then, you get a 5/4 beat with a slow–slow–fast–fast pattern:

• Example: the theme of Mission: Impossible

Iterate, and you get a 4x slow – 4x fast pattern, akin to alternating bars of 12/8 and 4/4. These may also be considered 5/4 or 10/4 to avoid alternating time signatures:

• Example: "tolerate it" by Taylor Swift.

Of course, you can also count 5/4 just like 4/4, but with five beats in a bar instead of four:

• Example: "Underground" by Eminem.

Or do the same with subdivisions of three instead of two. The result will be 15/8:

• Example: "Here Come The Bastards" by Primus.

And, you can naturally mix and match those beats into common time as well, which will usually still be labeled 4/4 for your convenience (or your confusion):

• Example: "Rich Girl" by Gwen Stefani.

The above pattern is very common in Latin American and in R&B music, and has its own name: tresillo.

Alternatively, you can take a common time bar and cut it short by removing one beat. If you do this with every second bar, the result is 7/4:

• Example: the bridge of "Heart Of Glass" by Blondie.

One can use multiple ways to arrive at different subdivisions of the same time signature, even within one song. Take, for example, the "Lost Kingdom" theme from Super Mario Odyssey, which is in 11/8^note or 11/16 if you want, so you don't have to use a ridiculously high tempo:

• The very first motif in the first four bars takes 5/4 subdivided into five beats of two, and adds a 3rd eighth note to the 3rd (middle) beat:

• The following motif takes 12/8 – 4 beats of three – and removes the 3rd eighth note in the last beat:

As you can see, these start out simple, but they may get complicated very quickly. Music can be weird sometimes. And some bands wallow in this rhythmical weirdness. For a whole genre built around Uncommon Time, see Math Rock.

Finally, a few things which would make little to no sense in time signatures and thus are to be avoided:

• Extremely large numbers: Awesome, but Impractical, as explained before.
• Non-integer numbers: Better notated as a multiple which is an integer. Something like a bar of 6.5/8 would be valid, but notated more comprehensively as 13/16, or two bars of 6.5/8 as 13/8.
  • Irrational numbers make extremely limited sense to use in a system based on ratios, if at all. Something like "π/4" is only written to poke fun at pieces making extensive use of Uncommon Time.
• 0 in the numerator: would indicate a timespan of zero. While not totally breaking maths, it adds no valuable information.
• 0 in the denominator: Dividing By Zero.
• Negative numbers: Only make sense in a very specific, pre-defined context. Even then, such things notated in ways which add less confusion:
  • Removing pieces from a preceding bar, i.e. 4/4 followed by a bar of –1/4: Use a time signature with a lower numerator, in this case 3/4.
  • Playing the contents backwards: Just notate it in backwards order.
• Complex numbers: Reserved for when physicists and/or philosophers have a useful concept of an imaginary frequency.
• Infinity: Infinity is not a number. "∞/4 time" is patent nonsense, just like "elephant/4 time" would be.
  • the ordinal number after Infinity: Stop.
• Denominators which aren't a power of 2: There is no defined symbol for something like a third note. Note values which are not a power of two are handled using tuplets. I.e. one bar of five "fifth notes", which are the same length as a whole note, would be notated in 4/4 using a quintuplet of quarter notes – five quarter notes with a bracket and the number 5 on top. "Play 5 quarter notes in the timespan of 4 in 4/4 time" has the same meaning as "Play five fifth notes in 5/5 time" without requiring an infinite amount of new symbols for all possible subdivisions of the whole note.

Tempo

Tempo is measured in "beats per minute". You take the bottom note of the time signature, and have that many of those notes per minute. Because tempos exist, time signatures are not objective measures of anything; a song that's in 4/4 time can be played at 60 beats per minute or 120 beats per minute. Time signatures determine how the music is structured; tempo determines how frantic it is.

Duration

Finally, there's duration. We've actually already covered parts of this. The most basic unit of duration in music is the whole note. It subdivides into half notes, which themselves subdivide into quarter notes, which subdivide into eighth notes, and basically further on down as far as you desire. Realistically, though, sixteenth notes are about as short as you're ever going to get. Here's an overview, including symbols^note This table uses Unicode symbols. Musical symbols are relatively new to the Unicode standard, so they may not be displayed properly on computers lacking a suitable font. GNU Unifont is a free and open-source font which supports all Unicode characters after installation.:

This can be continued indefinitely by adding more flags to the symbols. As said, note values of 1/32 or shorter are rare, and those beyond 1/128 may look impressive, but aren't very useful in practice.

One way to get note values in between those powers of 2 is to use dotted notes. Putting a small dot to the right of your note signifies a 1.5x duration, i.e. your original duration plus one note of the next shorter duration. Therefore, for example, a dotted quarter note takes up the same duration as three eighth notes, whereas a regular quarter note has the same duration as two eighth notes. As with many concepts in music theory, you can add dots to a dotted note again and again, appoaching a 2x duration at infinite. However, even notes with two dots, signifying a 1.75x duration, are extremely rare in sheet music.

Remember, though, that tempo determines the speed of everything; it's possible to have songs with mostly whole notes that nonetheless goes very fast (cf the second-to-last battle song from Final Fantasy X), as well as songs that are mostly eighth notes but go really slow (Ludwig van Beethoven's Moonlight Sonata).

And yes, if you're counting, that FFX song is indeed in 5/4. Moonlight Sonata, however, is not in 12/8, even though it sounds like it should be, what with the constant 3-note patterns. It's because the notes of the ostinato ("continually-repeated musical phrase or rhythm, only, this is music, so most of our terms are Italian loanwords") are written in a completely new duration: triplets. It's possible to notate three notes in a way that says, "Play these three notes in the same amount of time, tempo-wise, as though they were two notes." This can be really useful for occasional rhythmic flourishes. (Which Beethoven didn't do: it takes until halfway through the piece before a traditional, non-triplet subdivision even occurs. Well, Beethoven was more brilliant than we'll ever be; what can you do.)

Melody

A "melody" is a series of notes (which are pitches assigned a rhythm) which move towards a state of tension and then a state of resolution. Three-Act Structure in musical form! They typically stick to pitches that are found in the key they are using, and often form large, repeating patterns over the course of several measures; but just about any trope in music can be subverted, and these are no exception. Melodies are a prominent part of music, and people spend a lot of time studying them and how they work.

Chords

A "chord" is any set of three (or more) pitches that are meant to be heard simultaneously and take place at the same moment in the music. It should be noted that, while they are meant to be heard simultaneously, they might not be played simultaneously; think about a series of notes played on a harp, an "arpeggio," and you'll see how they form chords despite being sounded discretely.

The most frequently-used chord in Western music is the "triad," which corresponds to the first, third and fifth note of a scale or key and named for the note at the bottom, known as the "root". It doesn't have to be the scale or key that the song is written in; a song that consisted of just that one chord is still two chords short of achieving Three Chords and the Truth, and possibly pretty boring as well. Of course, even "Three Chords and the Truth" has been subverted, by Harry Nilsson's infamous "put da lime in da coconut and drink 'em bot' up" song — to this day, the only one-chord song that has ever gotten anywhere on the Billboard charts. (Dr. Luke is undoubtedly trying to achieve the second — when he's not getting sued by Kesha, at least.) Having said that, the single chord in Nilssen's song is not a straight major triad: it's a chord with four notes, in this case the 7th scale degree.

The I chord — the triad built of the first, third and fifth scale degree, typically represented by the Roman numeral for 1 — is one of the three chords in "Three Chords and the Truth." The other two are the IV chord (the 4th, 6th and 8th/1st scale degree) and the V chord (the 5th, 7th and 9th/2nd). These three together are easy to play and create a very effective Three-Act Structure if played as a "Chord Progression" of I - IV - V - I. The reason the Three-Act Structure works is because I, IV and V chords have specific emotional connotations. The I chord, the "tonic", feels stable and like it's comfortable right where it is. The IV chord, the "predominant" or "subdominant", feels like it's trying to start some trouble. And the V chord, the "dominant", feels as though it has been Left Hanging and wants to "resolve" to something — say, the tonic. (They're also three of The Four Chords of Pop, the fourth being a vi chord — the 6th, 1st and 3rd. This chord is minor, which is why the Roman numeral "6" is in lowercase; the other three are major.)

The study of how chord progressions resolve is an entire branch of music theory in and of itself, called "cadences." There are four main cadences, each with a helpful article:

• Authentic Cadence: dominant chord resolves toward the tonic, i.e., V–I
• Plagal Cadence: subdominant chord resolves toward the tonic, i.e., IV–I
• Deceptive Cadence: dominant chord towards other than the tonic, i.e., V–vi
• Half Cadence: any cadence resolving towards the dominant chord, i.e., ii–V

Other cadences exist as well, for further info see our Chord Progression article.

By chaining cadences together, we build our chord progressions. There are many recurring figures which are used time and time again in popular music, which are listed in our Chord Progression article. Some examples include:

• The Four Chords of Pop: I–V–vi–IV
• "Pachelbel's Canon" Progression: I–V–vi–iii–IV–I–IV–V, of which the aforementioned "Four Chords of Pop" are a shortened version
• the 50s Progression: I–vi–IV–V
• Three Chords and the Truth: I–IV–V–IV and others built from the I, IV and V chords, including:
  • the 12-Bar Blues: I–I–I–I–IV–IV–I–I–V–IV–I–I
• common Minor progressions: i-♭VII–♭VI–♭VII; i–♭VII–♭III–♭VII
• the Andalusian Cadence: i–♭VII–♭VI–v
• Vamps^note Not related to The Vamp or vampires. The term comes from the expression "Vamp till ready" in sheet music of the 1930s and 40s, referring to a short, often two-chord pattern to repeat until the vocalist(s) is/are ready to start, and has its origin in Old Fench avanpie.:
  • the Lydian Vamp: I–II
  • the Mixolydian Vamp: I–♭VII
  • the Dorian Vamp: i–IV
  • the Aeolian Vamp: i–♭III
  • the Phrygian Vamp: i–♭II
  • the Phrygian Dominant Vamp: I–♭II

Chord Quality

(directed viewing: Charles Cornell)

When analyzing a chord, a Western-trained ear tends to immediately go to the third of the chord, as it determines the chord's "quality." A major third results in a major chord, and a minor third results in a minor chord, which covers two of the three basic qualities a chord can have.

The third quality is for when a chord doesn't have a third at all. Such a chord is called a suspended chord because it sounds incomplete. Typically, such a chord will have a 2nd instead of its 3rd, or a 4th, leading to the terms "sus4" and "sus2". Suspended chords feel a lot like V chords in the sense that they feel unfinished and want to resolve to something, typically something with a 3rd. The fun part is deciding what kind of 3rd you're going to resolve to.

The following is an overview of how chord qualities are notated, with two examples relative to a C key:

For seventh chords, there are several combinations of thirds, fifths and sevenths with distinctive names:

Chord Configurations

Chords typically consist of, at the very least, the three pitches in their triad, but they do not have to be configured that way. What if, instead of the 1st, 3rd and 5th scale degree, you played it with the 3rd at the bottom, followed by the 5th, followed by an 8th at the top? Because you get new configurations by turning the chord upside-down, these variations are called "inversions," and every chord has (X - 1) inversions, where X is the number of notes in the chord (Non-inverted chords with the 1 at the bottom are in "root position." This is considered the default state for a chord and is not given special notation). Additionally, you don't have to play them in that particular order. What if you had the 3rd scale degree, a gap, the 1st scale degree, a gap, and then the 5th one? This chord would be in "open position," whereas the more traditional 3-5-1 is in "closed position." Open chords sound more impressive, but are harder to play: if the notes are distributed amongst several instruments (IE string instruments, which have a lot of trouble playing two notes at once), it's harder to keep the pitches in tune with each other; if you're on a keyboard, the chord becomes physically larger and requires bigger hands.

Because chords can have more than 3 notes, it is also possible to have chords that are only "half-open": a 7th chord (1-3-5-7) would be called half-open if you moved the third up an octave (1st, 5th, 7th, 3rd).

Note that there is a strange numbering convention for chords. You are only supposed to add every other note to a chord, though (as mentioned with inversions and closed position) you can absolutely configure them differently once you're done adding them. But the result is that anything beyond 1, 3, 5 and 7 is considered to be from the next octave up, and is numbered accordingly. A chord consisting of 1, 2, 3 and 5 is not numbered that way; it's considered a 9th chord, even if you close it up and play it 1-2-3-5. Likewise, a 1-3-4-5 chord is an 11th chord, and a 1-3-5-6 chord (very common in jazz) is a 13th.

It should also be pointed out that you don't have to include everything in a chord. Theoretically, a 9th chord goes 1-3-5-7-9, but in practice the 7th scale degree is often left out, and if not, the 3rd is. Typically, a chord is reduced to only four pitches. People who are dealing with 13th chords are typically very thankful for this fact, as 6 pitches at the same time may exceed the reach (or quantity!) of their fingers or hands. You can, of course, do the opposite; noted YouTube musician Jacob Collier reported being very excited when he found a chord that involves all 11 scale degrees of the chromatic scale and didn't sound like crap, and a god of choral composing named Eric Whitacre is known for massive stacks of notes; the chord at 3:04 in the linked recording has 14 individual pitches, including 11 diatonic pitches in a row — every in-scale note between E♭4 and A♭5.

And we haven't even started sharping or flatting anything yet. In addition to major chords (which are defined by having the 3rd be a major 3rd up from the root, and the 5th a minor 3rd above that — there is a mathematical relationship going on here because a 5th is seven half-steps above the root, and "7" does not divide evenly) and minor chords (which have the minor 3rd, 3 half-steps, between the root and the 3rd, and the major one between the 3rd and the 5th), there are also "diminished" chords where both intervals are minor thirds, and "augmented" chords where both are major thirds. Technically, any interval can be diminished (by removing a half-step from its normal value) or augmented (by adding a half-step). And when you start adding on additional members to the chord, all of them can be major'd, minor'd, augmented, diminished or perfect'd (assuming it could be perfect'd in the first place; you can't magically have a "perfect" 3rd just because you're adding on extra chord members).

Chords are another major branch of music theory because the possibilities of adding just about anything to the original triad, not to mention the question of how exactly to invert, open or half-open them, are almost limitless. Chord progressions and chord configurations, in particular, also play into the "art" part of music theory (IE how they will cause the listener to react), because different configurations don't have the same impact. Try going to the apronus.com Flash Piano, clicking the "Advanced" checkbox and then the "Chord" checkbox which appear afterwards, and trying the following chords: C4-D4-E4-G4; C3-G3-D4-E4; E3-C4-D4-G4. (If you unclick "Chord" in between each one, the page will actually save each chord as a button which you can press afterwards, aiding in the comparison.) These three chords are, technically, all the same chord — a C-major with an add9 — but as you can hear, they sound quite different, due to the varied ways they distribute the tension of notes that are near each other, and as such will have different effects on the listener. And then there's the question of what progression you plan to put around this chord. All the same questions we've asked about this Cadd9 can be applied to every other chord in the progression that leads up to it.

This stuff gets complicated, fast, but it's also some of the most fun parts of music.

Some music uses what are commonly referred to as power chords, which are technically not chords, as they are made up of a first/root and fifth, and sometimes the octave. Both versions give you two notes, and are more correctly a form of double stop, ^note  The name double stop comes from string instruments where you stop the strings when you fret them. (or triple stops). Like suspended chords, they are neither major nor minor.

Harmony is the study of what pitches sound good together and why. This overlaps with chords to a certain extent; the two are sometimes described as the "vertical" aspects of music (since you think about everything that's happening in one moment of time) as opposed to the "horizontal" aspects of melody.

Harmony is typically thought of as being "homophonic" — a melody over chordal accompaniment, like someone singing while playing guitar; or you could go even further and be "homorhythmic," — all parts using the same rhythm as the melody, but different pitches, like your typical SATB choir. But it does not have to be this way; "counterpoint" and "polyphony" are the business of creating multiple melodies that sound like they are all independent but are actually crafted to work together. Even admitting that people can do this is probably beyond the scope of this article; some of the greatest composers in history, like Johann Sebastian Bach and Giovanni Pierluigi di Palestrina, made their name solely by perfecting counterpoint (examples: Bach, Palestrina); in fact, Bach is rated by many the finest composer ever because of his mastery of this stuff. Entire styles of composition — canons and fugues — are devoted to the business of repeating the same melody with enough variation to create entire musical pieces. Do Not Try This at Home, at least until you've figured out how normal harmony works, but once you have, this is a place to go.

Consonance and Dissonance

Pitches that sound good together — 1, 3 and 5, for instance — are called "consonant" pitches. More often than not, though, they're not called anything at all, because the default in Western music is that all the pitches in any given chord are going to sound good together, always. When something doesn't sound like it fits in — when something sounds "dissonant" — it's kind of a big deal. Dissonant intervals are notes that are within one whole step of the basic notes of the triad — AKA, anything that isn't 1, 3 and 5. Given that 7th chords exist, it is obvious that this doesn't stop people from subverting the rule, and dissonant chords can sound very cool in the right context (for instance, the add9 in the previous section, which hopefully you enjoyed). However, as with all subversions, one should treat with care, and not attempt to subvert unless they're already comfortable with the rules.

Part of the reason you want to be careful with dissonance is because of another phenomenon called "voice leading".

(directed viewing: 8-Bit Music Theory)

Despite its name, "voice leading" is not unique to sung music; the word "voice" in music theory refers to a distinct line/part/aspect of music within the larger piece (bass, harmony, melody, etc). Voice leading is, instead, the business of controlling the number of pitches that change every time you switch chords. The more big jumps each voice has to make, the more dramatic and unstable a song sounds... which can be cool, but there are also going to be times when you want it to be smooth and calm. For instance, if you're doing a standard Authentic Cadence using Three Chords (and the truth), you're going from 1-3-5 to 4-6-8 to 5-7-9 back to 1-3-5. There are some consecutive numbers between those three chords, right? You could have one voice (say, a viola) go 3, 4, 5, 3 (or even 3, 4, 5, 5), and another (a violin) go 5, 6, 7, 8. Smooth, right? And easier for those musicians to play, which they probably will not complain about. And, of course, you can keep things really smooth by starting to reconfigure the chords themselves. If you put the 4-6-8 chord in 2nd inversion (1-4-6) and the 5-7-9 in 1st inversion (7-9-5), your bottom voice can play 1-1-downto7-backupto1, which is about as unchanging as it's possible to get.

Dissonant chord tones complicate these moving lines, or shut off movement lanes that would otherwise be available, because they have specific places they want to resolve to. In the above example, our hypothetical viola could go 3-4-5-5 or 3-4-5-3; both are viable voice-leading paths. But if we add a "dominant 7th" to the V chord — 1-3-5-8, 4-6-8-11, 5-7-9-11 (AKA 5-7-2-4), 1-3-5-8 — you've got this added 4 you have to resolve, and it almost has to go down to the 3rd — the "suspended 4th" is a well-known and extremely resolved-sounding chord progression. So whatever your other voices or instruments are doing, they have to be on either 1s or 5s in that final chord because the 3 is already taken. (You could double it, but one of the rules of voice-leading is also that you are not supposed to double the 3rd, because the results just sound weird.) And that's even before we get into things like "parallel fifths/octaves" (which is when two notes are a fifth or octave apart and then move in the same direction by the same interval; this sounds bad to most people), "hidden fifths/octaves" (two notes moving by different intervals but still in the same direction to finish a fifth or octave apart; this also sounds bad except in specific circumstances), "tritones" (covered already), and other various messes.

This gets extra confusing because, if properly written, voice leading can overpower the needs of functional harmony. The listener will accept a walking line that makes sense even if that walking line involves pitches that don't make sense in context. For instance, let's say you're writing a harmony for the bridge of the classic cheesefest Close To You (you know, "Why do birds suddenly appear") as performed by Carpenters, and specifically addressing the bridge section where the melody goes 5-6-7-6-5. Your harmony could go 1-7-6-7-1. Theoretically, you should not do this, because you're going to end up with a chord spelled 6-1-3-7 (and another spelled 7-1-3-6), which doesn't sound good in and of itself... but the listener won't care very much because the two voices have, in and of themselves, such strong and sensible motion. (To showcase this even more, a couple of exceptions to hidden fifths/octaves specifically involve walking lines, and this kind of movement is also critical to handling dissonance in counterpoint.)

Finally, dissonant notes, "color" notes, "chromatic" notes, are tricky to use because they're hard to play. When musicians hear dissonant notes, they tend to go "Oh, Crap!", because all their training is that this should not be happening. So, even if they're supposed to do it on purpose, they may have trouble doing what they're told. (Obviously, additional training and experience will help with this... but "additional training and experience" may not be something your musicians can obtain at short notice.)

Staff notation

A staff is a grid-like system which denotes rhythm and durations horizontally, and pitch vertically. A staff consists of five parallel lines. The pitches A, B, C, D, E, F and G are placed vertically, with the note head either on a line or between two lines. Higher pitches are further up vertically, and lower pitches further down. If your pitch does not fit within this system, it may be extended appropriately by adding ledger lines. Ledger lines are only drawn a short distance fitting one note each to avoid visual clutter. (Well, at least attempt to avoid or reduce clutter.)

Clefs

So, how are we supposed to know which pitch is on which line? And what if I defined something like "middle B is on the middle line" and then want to notate a pitch three octaves up; how is that supposed to fit into this puny staff!? No worry, that is what clefs are for. They are placed at the start of a staff and act as a sort of anchor for your pitches. A clef is basically shorthand for "this particular line shall always be for this specific pitch, until another clef follows or the music ends." There are several types of clefs, coming from notation for different voices and instruments:

• The treble clef or violin clef is a G clef. It defines the 2nd lowest line of the staff as the place for the pitch G, more specifically "middle G", G4. The symbol is actually an extremely stylized letter "g", which became more and more swirly in musical handwriting over the past centuries. This is usually the first clef anyone reading sheet music, learning an instrument or singing in a choir will be familiar with. It is the most common clef symbol; so much so that this clef, as well as individual note symbols, are synonymous with the word "music" when representing it in an image, even out of its intended context.

• The bass clef is an F clef. It defines the 2nd highest line of the staff (the 4th lowest, between the two dots) as the place for the pitch F, more spefifically "low F", F3. This clef is a very stylized letter F: the vertical bar was made into more and more of a curl over the centuries, and the two horizontal lines were reduced to two dots.

• Less common is the alto clef, which is a C clef. It defines the middle line (3rd lowest) as the place for the pitch C, more specifically C4. Like the bass clef, this clef is also a very stylized letter, this time a stylized C: the serifs at both ends extended and became extremely exaggerated over time, focusing the view onto the middle line, where the pitch C resides.
• Similar to the alto clef is the tenor clef. It is also a C clef, and looks like the alto clef, but it is placed one line higher on the staff, so C4 resides there, instead of the middle line.

Key signatures

After the clef comes an arrangement of sharp or flat symbols called the key signature. It shows the performer in which key is in, i.e. which note harmony and melody are based on and which scale and mode to use. The arrangement of those symbols may look arbitrary at first, but follows a pattern – once again – derived from the Circle of Fifths: for sharps they are on the positions for F, C, G, D, A, E, B, in that order; each of these pitches is a perfect fifth apart from the next. Below is a table with all possible sharp key signatures:

For flats, the same order is used, but backwards, starting on B. This gives us the following flat key signatures:

Note: Because of the way modern instruments are tuned, the following keys are equivalent:

• F♯ Major/D♯ minor (6 sharps) and G♭ Major/E♭ minor (6 flats)
• C♯ Major/A♯ minor (7 sharps) and D♭ Major/B♭ minor (5 flats)
• C♭ Major/A♭ minor (7 flats) and B Major/G♯ minor (5 sharps).

Time signatures

The clef and the key signature are followed by the time signature, as discussed previously. Unlike clefs and key signatures, the time signature is not repeated on every new line of staff; only when the time signature is changing.

Notes and Rests

As discussed previously, pitches held for a certain duration are represented with notes. Equivalent durations during which no note is played are represented with symbols called rests. The following overview shows more or less commonly used note and rest values:

Notes change position vertically depending on which pitch is to be represented, while rests always stay in the same position, as they do not represent a pitch, but rather an absence of any pitch.

Other symbols and text

Other symbols include:

• Bar lines: delimit each bar from each other, to make it much easier to keep track of rhythm.
  • Repeat lines: indicate that the section between the opening and closing repeating lines is played twice. It has two thick bars with either two dots to the right (begin of repeated section) or to the left (end of repeated section).
• Dots:
  • Dots to the right of a note indicate that this note has a duration 1.5x its normal value. (This can be extended with 2 dots for 1.75x, 3 dots for 1.875x and so on, but this is very uncommon.)
  • Dots above or below indicate that these notes are played staccato, i.e., short, abrupt and with force.
• Bows:
  • Bows between notes of the same pitch are ties These notes are equivalent to one note with the sum of all their durations.
  • Bows between notes of different pitches are slurs. Slurred notes are performed with a contiuous rather than abrupt change of pitches, i.e. gliding to the next pitch instead of stepping. This is only possible with a few instruments such as the trombone, and with the human voice.
• Wedges:
  • Pointing to the left (<), it indicates a crescendo: music is to be played increasingly loud and stay at the new loudness after the wedge symbol ends.
  • Pointing to the right (>), it indicates a decrescendo: music is to be played progressively quieter and stay at the new, reduced loudness afterwards.
• Fermata: a dot in a half circle. This symbol appears above notes which are to be extended arbitrarily long, as the performer sees fit. These often appear at the very end of a piece of music.

Written text may also be included above or below the staff to provide additional instructions. In classical music, these terms are often in Italian. Some examples include:

• Loudness or Dynamics, from loudest to quietest: ff (fortissimo, very loud) – f (forte) – mf (mezzoforte) – mp (mezzopiano) – p (piano) – pp (pianissimo, very quiet).
• Tempo:
  • There are lots of terms indicating different tempos; however, these are usually limited to classical music and are more ambiguous than just writing the BPM number.
  • accel. (accelerando) indicates music getting progressively faster.
  • rit. (ritardando) indicates music getting progressively slower.

Tab notation

Tabs are another method of notation used for fretted string instruments, most commonly guitars. Tab is a shortened form of tablature. While many view tabs as a more recent development for those who do not read standard notation, tablature has has existed for centuries, and is older than standard notation. Tabs consist of horizontal lines; each line represents one string of your guitar. The tuning of each string is shown on the leftmost side. Because this also shows the lowest pitch playable on each string (fret position 0), no clef is needed. The individual notes are represented by numbers that indicate which fret position to hold. Various symbols may be used to indicate ornamentation and rhythm.

Further reading

• https://method-behind-the-music.com/theory/notation/
• https://www.britannica.com/art/musical-notation
• http://tobyrush.com/theorypages/

There are many, many, many instruments used for music, starting with one's own voice and hands (clapping them together or slapping other things for percussive effect) and going on from there.

All instruments have one thing in common: a surface that vibrates to produce sound. Since this isn't a useful taxonomic metric, instruments are typically grouped into a number of categories based on additional features they all have in common with each other:

• The human voice is powered by the vocal cords, which vibrate to produce pitch. Consonants and vowel sounds are shaped by the mouth and tongue. Certain consonants are "plosive" (like P and T) while others are "sonorant" and can actually be held on a pitch (M and R). The original instrument, the human voice is quite versatile and should not be underestimated; there is an entire field of music, A cappella, which utilizes nothing but singing. Voices are typically sorted into Voice Types, both for musical and dramatic purposes. While voices can be used in relatively unregulated quantities, it should be pointed out that they are often used in very close configurations of harmony: an experienced singer typically has a vocal range of about two octaves, a 15th. If you run a bow over the strings of a violin, you will find that it has a range of a 14th — long before you start putting fingers to strings to increase their pitch. The human voice is also very powerful, because it can transmit information not just via pitch, tone and timbre, like other instruments can, but also by lyrics. This means it is possible to overuse voices if you're not careful, overwhelming the listener with too much information that they can't meaningfully parse.
• Stringed Instruments have, as the name would suggest, strings. However, they also have wooden bodies, the bottom panel of which vibrates to create sound, and the strings are manipulated by a "bow." Pitch is controlled by using a finger to manually shorten the length of any given string.
• Woodwinds are powered by the human lungs. In most of them, the vibrating portion is called a "reed"; some woodwinds have two reeds. Reeds need to be replaced frequently, and creating new ones by hand is something any woodwind player eventually masters. Flutes are strapped into this category because they have more in common with woodwinds than anything else, even though their reeds are built into the body of the instrument and do not need to be replaced.
• Brass instruments are also powered by human lungs, but involve a tubular resonator which creates sound, the length (and pitch) of which is changed by the control mechanisms on the instrument. This, not metallurgical composition, is the defining element of a brass instrument (hence why saxophones are woodwinds, and why a traditional wind quintet includes a French horn; earlier ancestors of it, "natural horns", did not have this feature).
• Keyboard instruments are clumped together because they're played by a person sitting in front of a bunch of keys. Each key is attached to an individual noise-making mechanism that is tuned to a specific pitch. The mechanisms themselves vary: on a piano they are strings which are struck by a hammer apparatus; in an organ they're connected to a phalanx of woodwinds; on a harpsichord they are strings which are plucked. So as you can see, here's where the category criterion starts to change from "They make noise the same way" to "They are played the same way".
• Percussion is the family of things that are whacked. From drums to gongs to tambourines, they all have one thing in common: you hit them, and the thing that you hit vibrates to make noise. Percussion instruments are typically thought of as being without pitch, but the family also includes the xylophone, the vibraphone, the marimba, and most kinds of bell (technically, the piano also belongs here, which further shows how the categories are breaking down).
• Plucked Strings are not really a classification that is recognized internationally (you won't find an article on them on The Other Wiki, for instance), but is a way of differentiating between bowed string instruments and things like guitars, ukulele and the harp (seriously, when's the last time you saw someone playing those with a bow?). Again, the only major difference is the way the strings are manipulated, but the change opens up a lot of techniques (harp glissandos, rhythmic guitar strumming, etc) while roping off others.

Each instrument is played a certain way, and having things in common with other instruments does not guarantee much of anything. A guitar has 6 strings and a ukulele has 4, so you can't play things exactly the same on them. And forget things like "piano vs. harp". While a piano has 11 keys per octave, the harp has 7 strings and sharps or flats them using pedals; it can't deal with accidentals nearly as easily as a piano does, and a comparatively chromatic piece, easily played on piano, can be ruthlessly challenging on a harp ("My working title for this piece was 'Pedal Hell' ").

Prior to the late 19th Century all instruments were acoustic. In a performance setting listeners directly heard the vibrations made by the musicians. With the advent of microphones, as well as devices such as electromagnetic and piezo pickups, there were electric instruments. These still had the the musicians play as before, but the listeners hear an amplified version which may have different sound qualities. They can be heard unamplified. Later on electronic instruments were invented where the sounds are produced electronically, although a musician triggers it. There is no vibration to be heard without an external speaker of some sort.

There are a number of different genres of music, such as Jazz, Classical, Klezmer, Rock & Roll, musical theatre, and more.

A scholar named Philip Tagg has divided music into three basic categories:

• Art Music is meant to be listened to attentively and may require a certain amount of music-theory background to appreciate.
• Popular Music is meant to be enjoyed by the masses, not just music students; is disseminated via mass media; and is typically sold as a product meant to turn a profit.
• Traditional Music, sometimes called Folk Music, is transmitted orally and derives from a particular culture or region. It is sometimes called "World Music".

Hallelujah Chorus

Through the Fire and Flames

Genres are further subdivisions within each of these larger categories. Most genres are defined by combinations of the things already discussed: specific chords or cadences, specific rhythms, specific instruments, specific time signatures, specific techniques, specific languages or lyrics or subject matter, and so on. For instance, "Rock and Roll" music is defined partially by how it uses drums, whereas a song does not qualify as a Barbershop composition unless dominant-7th chords are used enough times.

Very few (if any) musical acts ever stick to a single genre. True, an act may be predominantly country, or electronic, or choral, but almost everyone mixes and matches based on the kind of music they wish to create. "Genre Mashup," in that sense, should actually be considered the norm rather than an exception. This is especially true as various acts gain popularity and the landscape shifts to accommodate them.

A song does not have to stay in the same key for its entire duration. If it doesn't, it's called a "key change" (in common parlance) or a "modulation" (in technical-scientific-music-speak).

Modulations typically follow specific rules that are similar to those of voice leading: specifically, the two keys should be as similar as possible.

• Under the rules of Art Music, of the sort that Mozart followed, this means that the new key should be a fifth higher or lower than the original, because the new key signature will only be different by one sharp or flat. (More on this mathematical fact shortly.)
• Under the rules of Popular Music, it's possible to simply go up one half-step or one whole step — the so-called Truck Driver's Gear Change. If you go up a whole step, the resulting key will be two sharps or flats different than the original one, but a half-step key change typically involves changing from a key signature written in sharps to one written in flats, or vice versa. From the standpoint of technical music, the two keys have nothing to do with each other... But it works artistically because they sound so similar.

• The Art-Music standard is that a song should change to its "relative major/minor" key, which means the song should, if it starts in minor, switch to the major key that is a minor 3rd up — such as a song in A minor becoming C major — and if the song starts in major, move to the minor key a minor 3rd down — e.g. C major down to A minor. This is because of the modal relationship discussed earlier: the Aeolian mode, the one starting on the 6th scale degree of the matching Ionian scale, is minor. In other words, the key signature for a key's relative major/minor is identical to that of the initial key... And in terms of making the fewest number of changes to a key-signature graphic, "none, you're just thinking of a different note as being tonic" is hard to beat. Modern examples example of this technique can be heard from the Act II opener to Dr. Horrible's Sing-Along Blog, "My Eyes", in which one character sings in minor and the other in major (and, at the end, they duet); and in "Suteki Da Ne" from Final Fantasy X, in which the verses are in minor and the chorus in major.
• Popular Music rules allow you to simply flip between the major and minor of any given key — "Happy Together" by The Turtles, "The Sign" by Ace of Base. These are called "parallel major/minor" keys, and, again, typically involve flipping from a sharp key signature to a flat one, but it works because the tonal center is maintained (unlike the relative major/minor keys, where the key signature is maintained).
  • This is also a good time to introduce the concept of "melodic minor," which is neither a key nor a mode but rather a modification. "Natural minor," a.k.a. Aeolian mode, has three scale degrees that are different than major: in addition to the lowered 3rd scale degree which defines the minor sound, they also have a lowered 6th and 7th. "Melodic Minor" re-raises those two notes so that the only difference between it and major is the 3rd. Again, though, "Melodic Minor" is not a key with a signature; it has to be denoted using accidentals.
  • This is also a good time to mention the "Picardy Third." If you've ever heard a song that spends most or all of its time in minor, but then throws the chord of its parallel major right at the end just to feel more complete (e.g. "Happy Together" by The Turtles), well, that's a Picardy Third. There, done with that bit.

This gets interesting because now we're going back to physics and math.

When two separate instruments play two separate pitches, and the pitches are perfectly in tune, they will create a sympathetic vibration together — AKA, another pitch. This pitch called an "overtone". Its exact hertz is determined by what the two "real" pitches are, but typically follow the "harmonic series." The harmonic series is... complicated, so we'll just link you to a helpful YouTube video that explains it.

The reason this is significant is because harmony has a basis in nature. We don't think these things sound good because Humanity Is Insane, we think they sound good because physics. It's math that makes things sound good. And you can't argue with math.

"Can I create overtones using only a single instrument?" you may ask, and that is a very good question. The answer is that it depends on the instrument. First off, even on instruments that can make more than one pitch (EG violin or guitar), there's Some Dexterity Required to play them perfectly in tune. Second, even on keyboarded instruments, pitches are not perfectly in tune. Pianos use equal temperament, which is the best compromise that makes any given key sound like it's in tune with any given other key... but they're only approximations. To create an overtone by pressing (say) F5 and G5, you'd have to tune them just sliiightly different than if you wanted to create an overtone between F5 and G♯ 5/A♭5... and so on for all 85 other keys on the keyboard. While synthesizers could potentially be programmed to tweak the frequency of any given key depending on what other keys are being played at the same time, this also assumes that proper tuning could be achieved for any given chord — eg, for the third of a chord to tune properly to the fifth might require the third to be at 1,234.5 hertz, whereas to tune properly to the 7th it might need to be 1,256.7 hertz. (The linked YouTube video actually covers this too.) Technology Marches On, but we have yet to invent an instrument that can make two pitches sound like one pitch — or have them near each other but still sound good.

This is a simple way to add color to a song.

Let's say you have a IV chord — 4-6-8 — in first inversion: 6-8-4. You know what would be a similar chord? A vi chord, 6-8-3. Two of the three pitches are the same, after all. So, where you'd normally use the IV-in-first-inversion chord, you write a vi chord instead. The important part is that the vi chord is essentially pretending to be a IV chord in this case — it's serving the same harmonic function.

In general, you can substitute Chord B for Chord A as long as they have two pitches in common. However, that's where things start getting really wacky, because the pitches can include chord extensions. Did you know you can substitute a F♯7 for a C7? They both share E♮ and A♯. "But hold on," you may say, "A dominant-7 C chord doesn't have an A♯ in it." And you'd be right... but it does have a B♭ in it, and B♭ Lives A Double Life as A♯. When the same piano key has two names, said names are described as "enharmonic equivalents." (Also, F♯7 for C7 is a tritone substitution and it's pretty out there, but it's a good demonstration because it shows just how dramatically you can use this technique.)

The Circle of Fifths is not really a musical figure in and of itself; instead, it's a tool that helps you put together harmonies and chords. It does this by listing all 11 notes in a chromatic scale (that is, white keys and black keys) and showing how each one is a perfect 5th (7 half-steps) above one pitch and a perfect 5th below another. If you keep going around the Circle of Fifths this way, you'll end up right where you started, which is pretty neat.

The circle of fifths, incidentally, is also a neat guide for writing key signatures. As mentioned above, C major / A minor is the only key that can be played on a piano with all white keys; its key signature is a complete and total blank. But if you go clockwise around the Circle of Fifths, the next entry — the one at 1 o'clock — is G major (or its relative minor, E minor). This key signature involves 1 sharp. Likewise, the key at 11 o'clock, Fmaj / Dmin, has a key signature of 1 flat.

The reason this works is because each pitch has a logical relationship to each other pitch. The Circle of Fifths simply illustrates that, making easy for you to figure out the most efficient way to get where you're going.

Much has been discussed about the Circle of Fifths and how moving around it can be used to create specific emotions in the listener, which is — again — the whole point of why we're studying music theory in the first place. For a fairly rapid, if mind-blowing, dive into the subject, watch Adam Neely's talk on the "brightness" of modes, followed by the 8-Bit Music Theory's study of use of deliberate brightness and darkness in the soundtrack of Persona 5.

The circle of fifths is most useful when attempting to change keys. As mentioned previously, dominant chords feel unstable, and have a chord they want to resolve to — specifically, a fifth down. Consequently, the V chord of your new key can be a very effective way of setting up the upcoming transition. Which, by coincidence, leads us to...

Ongaku Concept

Adam Neely

With this topic, we have officially graduated into more advanced music theory — in fact, secondary dominants are, almost literally, the foundation of jazz. This concept makes plenty of sense on paper, but can be difficult to implement in actual composition. Fortunately, we've already discussed its two ingredients: Chord Substitution, and the Circle of Fifths. "Secondary Dominants" is when you do a Chord Substitution (IE Chord B pretending to be Chord A) that is specifically meant as a V-I authentic cadence, with the Chord Substitution coming from a different key.

That's still kind of a lot, so let's explain.

One of the best ways to emphasize the importance of a chord is by having something resolve to it. Obviously, if you want to emphasize your I chord, you precede it with a V chord. But what if you want to emphasize something else, say a iii chord or a V chord? Simple: precede it with a major chord that is a fifth above it. The problem is that dominant resolutions don't work unless chord-that's-fifth-above is in major, which isn't true for these two example chords. If you are sticking to white keys or diatonic scale degrees, the chord that is a fifth above a iii chord is a diminished 7th, which just doesn't sound very good; likewise, the V of 5 is ii, which in diatonic scale degrees is minor.

Thus, secondary dominants. The scientific explanation is that we are borrowing chords from other keys to create a secondary, artificial, dominant resolution to a chord that isn't I. The practical explanation is that we are just taking chords and making them major by adding on accidentals. Let's say we're in C major, and trying to have a V of V (notated as V/V), for a chord progression of II - V - I (equivalent: V/V - V - I, two authentic cadences in a row). Our naturally-occuring ii chord is D minor, D-F-A. A major II chord isn't naturally found in, well, basically any key (you need a mode for it), but D-major as a chord in and of itself does in fact occur in various places — Dmaj, for instance. Technically, we are importing it from Gmaj where it serves as the naturally-occurring V chord to G, which is the chord we are trying to resolve to; technically speaking, we are shifting, for this one chord, into G major, a shift so swift that a key-signature change isn't necessary. (Nor, frankly, would it be practical, because — due to the nuances of music notation — key-signature changes are only allowed to apply to entire measures, and "one chord" is typically swifter than a measure.) It's a secondary dominant.

When you import a chord to make a secondary dominant, you almost always use a dominant 7th chord, because it feels extra-unstable and leads the listener to expect the authentic cadence. This is especially important if you are trying to do the secondary dominant of a IV chord, because the V-of-IV is... I, which is about as opposite of "unstable" as it's possible to get.

It is possible to repeat this process of borrowing dominants of dominants, but tertiary dominants (V/V/V) are already exceedingly rare. After twelve iterations, you cycle back to your original V chord.

Tritone substitutions are a vaguely related concept, in which you replace a dominant chord with the chord a tritone away for a similar dominant function. However, instead of taking a V of a V chord, you take the V of a ♭V chord – i.e. one semitone down, a tritone away from the V chord. The result is a ♭II chord which fulfills an equivalent role to a V chord. In notation, the resulting chord usually has the symbol "Δ-sub" added. The Phrygian mode, as well as the Phrygian Dominant scale, contain a ♭II chord by default, and tritone substitution may explain why the flat II chords resolve back to the tonic chord so well.^{What about Locrian?}Locrian also contains a ♭II chord, but it is forced to resolve to an unstable i^o chord. Also, as the Locrian mode contains the ♭V chord used for this procedure, the resulting tritone-substituted V chord from the Locrian mode would be ♭V/♭V – or I, the major tonic chord.

Unlike secondary dominants, tritone substitutions cannot be iterated, as the tritone-sub of a tritone-sub of a chord is just that original chord again.

For a long time — certainly for most of its history — music could only be consumed in a live environment: by physically going to a location where a musician was performing and consuming it in that musician's presence. But sound is just a physical phenomenon, so all you need is a way to encode that sound physically and then have something interpret the encoding properly, and ta-da, you can reproduce music. The first way humans did this was sheet music, or at least its precursors; the earliest written-down musical document is from Iraq in 2,000 BCE. This had the downside of the something-interpreting-the-encoding — namely, a different human musician — having access to different instruments and different levels of ability as the original, but it was better than nothing. And, as human continued to advance in mechanical and electronic technology, they invented the phonautograph — the earliest known technology for recording sound, predating Edison by thirty years — in 1857. From that point on, it became possible to preserve not only music but a specific performance of that music, and all bets were off.

Today, music is still consumed in a live environment: choirs and orchestras perform today, bands give concerts, and people busk on the street. That said, the business of recording music is much different than it has been in the past. Historically, one's hope was to capture a live performance — get John, Paul, George and Ringo to start playing, hit "Record," and hope no one bollixes it up. But with further advances in technology, things are now quite different. (Heck, they may have even been different back then!) In a studio recording environment, it is typical for a single musician to perform at a time, so that recording engineers can capture that instrument's sound without any sort of bleed-over from other musicians and/or instruments ("We can't use this track! You can hear Ringo shouting, 'I've got blisters on my fingers!' He was in another room!"). These are then combined after the fact by sound engineers to create the illusion of an everyone-at-the-same performance... but with the sound engineers maintaining complete control of volume, tempo and other elements, allowing them to blend one performance back into the mix, bring it out, speed it up (on purpose), slow it down (on purpose), add additional layers, and more.

The possibilities of studio recording has led to the concept of the recording studio as an instrument, in which the pre-recorded, assembled-in-post-production version of the song is intended to be the definitive version... and, in some cases, the only version that can actually be created. "Bohemian Rhapsody" by Queen, for instance, involves the "Self-Backing Vocalist" trope one hundred and twenty times, an entire choir of Freddies Mercury, which complicates efforts to replicate it live. First off, even if we could clone Mr. Bulsara (literally, not just in the Freddie Mercopy way), the sheer physical logistics of getting 120 singers on a stage and into microphones at the same time are daunting. Also, what do you do with them when you're done?—take them out back, shoot them, and clone 120 more for the next show? A better solution would be to hire a choir (containing a regrettable zero instances of Freddie Mercury), which must be paid and brought with you on tour... Meaning you're spending an awful lot of money on salaries, transportation, hotel fees and stage logistics for approximately 68 seconds of music per tour date. (The truth is that you can perform "Bohemian Rhapsody" live, but it requires either serious compromises or taking "Awesome, but Impractical" to new heights.) And let's not even talk about "Tomorrow Never Knows" with its weird pitch-bending, backwards electric guitar and more.

There is, of course, a middle ground to this, consisting of recorded music that can be performed live but wasn't on the version that is released. Some songs just copy-paste the same high notes over and over again, for instance. This can be taken to an extreme by having the soloist lay down multiple versions of the vocal line and having the engineer assemble the final vocal track from pieces of all three, moving word by word or even syllable by syllable.

While much of this was historically done on magnetic tape, the advent of the personal computer made recording hardware more portable — and more accessible. Digital Audio Workstation software, the most famous of which is probably Pro Tools, has supplanted and even replaced the giant stereotypical mixing board. While such software used to cost in the realm of $500 USD, Apple started packaging "Garage Band" in with its computers for free, and there are now open-source (IE free) version that can be downloaded to any computer. While none of this includes actual microphones, those can be gotten fairly easily; if you're really excited, your handheld personal computer — more commonly known as your "smartphone" — has one. The result is a plethora of home recording artists who compose, perform, record, mix and master entire works of music all by themselves. Examples include One-Man Band multi-instrumentalists like bill wurtz, contemporary A cappella artist Peter Hollens, and does-both-at-once extraordinaire Jacob Collier.

As with anything about music, this has also resulted in flame wars. While it's easy to point at the live-music purists and claim they are just conservative sticks-in-the-mud, the fact remains that live performance requires a minimum level of skill and competence which modern studio music does not. Additionally, a live performance is an act of communication between musician and audience, creating new heights of energy that a single human being, listening to a recording in privacy with no other people to interact with, simply will not. However, insisting that live performance is the only true and meaningful benchmark is to also insist that Bohemian Rhapsody is not a worthwhile or valuable artistic achievement — Insane Troll Logic if ever there was any. (There have been some really killer covers of the song which maintain its basic shape but cut down the amount of choral work to make it more achievable. Queen themselves perform most of it live, with the choral section being played directly from the album over the PA system.) Additionally, advances in computer technology means that even amateur home musicians have access to professional-level (or nearly-professional-level) hardware and software, allowing a much larger variety of musicians and music to present themselves to the world at large. Sturgeon's Law will always apply, but if you double the number of artists, you also double the number of artists in the 10%-that-aren't-crap segment, and that's not exactly a bad thing. There will never be a definitive answer over whether recorded music is better than live music, partially because — to a very real extent — it's an apples-to-oranges situation.

One of the... interesting elements of music is that almost everything has more than one name, or more than one way of describing it. Here we're going to go over some of them.

• Major and Minor: As mentioned, these are technically modes. It is acceptable to refer to something as being in "G Aeolian," though most people will look at you funny if you do.
• Enharmonic Equivalent: This is when the same pitch goes by multiple names. The piano key right below an F, for instance, can either be called "E" or "F♭". And we've been over black keys way at the start. This is, obviously, annoying, but is also important for spelling. If you're trying to spell a C-E-G chord, well, obviously, "C-F♭-G" isn't right. (It doesn't even have a vowel in it.) Of course, it also gets worse than that, since that E we were talking about earlier could also be a D𝄪 (double-sharp). Fortunately, it won't be often.
  • Enharmonic Equivalents are typically only seen in one context: weird and rapid key changes. This can be jazz, or it can be a Truck Driver's Gear Change. As mentioned when we discussed "voice leading," music is easier to perform if as few notes change over time as possible. In certain circumstances, you'll find a note that's in common between your two keys... except that in one of them it's a G♭ and the other it's F♯. It'll sound fine to the listener — in fact, it'll sound more stable, because (again) the less change, the better, and the performer will be happy once they realize that they're just supposed to stay on the same note... but it might take them a while to figure that out.
• Augmented, Major, Minor and Diminished Intervals: As mentioned previously, you can augment and diminish any interval whatsoever. See where this is going? A perfect 4th is 5 half-steps, a major third is 4 half-steps... A "diminished 4th" is also 4 half-steps. Again, this is mostly necessary for spelling. The notes in a chord always have to be in thirds above the root of that chord, so at times you may need to fake your chord's spelling with (say) an augmented 3rd, because you're just not allowed to have a 4th.

A

• Accidental: a symbol in front of a particular note, signifying a change of pitch:
  • Sharps ♯ and Flats ♭
  • the Natural accidental ♮, signifying that a previous sharp or flat no longer applies for following notes of this pitch
• Alto: a register of low pitches. In vocals, alto refers to the lowest register of women's voices, second only to contralto.
• Arpeggio: to play the individual notes of a chord in rapid succession.
• Augment: to raise (sharpen) an interval by a semitone.

B

• Bar: see measure
• Bar line: a line which acts as a delimiter between two adjacent measures, showing where one measure ends and the next begins.
• Baritone: a register of medium pitches. In vocals, bariton refers to the middle register of men's voices.
• Bass: a register of very low pitches. In vocals, bass refers to the lowest register of men's voices, second only to contrabass.
• Beat: unit and "building block" of rhythm.
• Blues: a genre/style of music very broadly characterized by extensive, often complex harmonies adding in harmonies outside of the main key of the song. The characteristic off-key pitches are called blue notes.
• Bridge: a part of a song between two sections which not repeated.

CDE

• Chord: a set of pitches creating harmony.
• Chorus: a section with consistent melody, harmony and lyrics which is repeated throughout a song.
• Clef: a symbol defining the position of pitches on a staff. From French clef 'key'. There can be only one clef for a single staff at the same time.
• Common Time: 4/4, by far the most ubiquitous time signature.
• Counting in: to get performers ready for a particular rhythm by counting the beats of one measure (if necessary, also count the subdivisions)
• Crossfade: a composition or a mixing technique to make two songs fade into each other seamlessly.
• Cut Time: 2/2, a time signature without subdivisions often used for marches.
• Diminish: to lower (flatten) an interval by a semitone.

FGH

• Fade: two songs transitioning into each other seamlessly.
• Falsetto: to sing with a register noticeably higher than the usual register. Also called "head voice".
• Fermata: to lengthen the duration of a note by an arbitrary amount. The accompanying symbol is also called fermata and often appears at the end of a piece of music.
• Flat: lowered in pitch by one semitone. Symbol: ♭ (flat or B)
  • flatten: to lower in pitch by one semitone, adding a ♭.
• Glissando: to slide as seamlessly as possible between starting and ending pitch in an interval.
• Grace note: a short-duration note played before or after a particular note, often used for accentuating it or creating smoother melodies.
• Half tone: see semitone.
• Harmonic: a higher pitch frequency which is either 1.5x or an integer multiple of the base frequency in question. Integer multiples are also called overtones.
• Harmony: the interplay of pitches, melodies and chords in a piece of music.

IJ

• Interval: the "space" between two pitches, as a ratio of the two pitch frequencies.
• Instrument: any device used to produce music.
• Instrumental: a piece of music involving only instruments and non-descript vocals, but no recited text (lyrics).
• Intro: the section of music at the beginning of a song. Songs may omit an intro and start directly into the first verse or chorus.
• Inversion: modification of a chord by moving one of its pitches up or down an octave.

KL

• Key: the particular base pitch (see tonic) and scale a piece of music is using.
• Key signature: a set of accidentals at the very beginning of a piece of music, indicating a permanent shift of one semitone for the corresponding pitches in all octaves. It tells the performer which key to use. A key signature can have up to seven sharps or up to seven flats, as there are seven distinct pitches between an octave in most scales.
• Leitmotif: a characteristic melody or rhythm figure which is repeated throughout the entire piece of music very often.
• Lyrics: poetic text accompanying a piece of music. Music without lyrics is called instrumental.

M

• Major:
  • for two intervals or chords which only differ by one semitone, the one with the higher semitone relative to the base note.
  • a Major scale, the Ionian mode of a diatonic key.
• Measure: a rhythmic unit, often encompassing a particular rhythmic motif. Measures subdivide into beats. Also called bar.
• Minor:
  • for two intervals or chords which only differ by one semitone, the one with the lower semitone relative to the base note.
  • a Minor scale, usually the natural minor, the Aeolian mode of a diatonic key.
• Mode: a scale obtained by starting on a different point (degree) of the original scale.
• Melody: a sequence of pitches played or sung throughout a piece of music.
• Mezzosoprano: a register of medium pitches. In vocals, mezzosoprano refers to the middle register of women's voices.
• Natural: absence of sharp or flat modifiers. Symbol: ♮. This symbol is also used to signify that a previous ♯ or ♭ does no longer apply.

NO

• Note: a symbol in musical notation, giving information about the pitch and the duration of a tone.
  • Notes may also refer to the entirety of musical instructions for a particular piece, see also score.
• Octave: two pitches in a 2:1 ratio. The name comes from the fact that most scales used in Western music use 8 steps to reach this 2:1 ratio ("the next octave").
• Ostinato: a short arrangement of notes which is repeated for a longer time.
• Outro: the last section at the end of a song. Songs may end without an outro or use it to fade into another song.
• Overtone: integer multiples of a particular pitch. See also harmonic.

PQR

• Pitch: a particular frequency including its natural overtones.
• Power Chord: a chord consisting only of the base/root note and the fifth, and sometimes the octave.
• Pre-Chorus and Post-Chorus: parts of a song which lead from one section into the chorus or out of the chorus into the next section, respectively. May or may not be repeated throughout a song.
• Register: a particular range of pitches an instrument or a singer is capable of playing or singing.
• Rest: a period of silence, absence of any notes. The rest symbol determines the duration of the rest.

S

• Scale: a set of pitches with defined intervals, usually spanning one octave.
• Scale degree: one particular pitch within a scale, numbered from left to right.
• Score: the entirety of written musical instructions in order to perform a piece of music.
• Semitone: smallest difference between two pitches in the default Western pitch system (12-TET), 1/12th of an octave.
• Sharp: raised in pitch by one semitone. Symbol: ♯ (sharp)
  • sharpen: to raise in pitch by one semitone, adding a ♯.
• Sheet music:' written instructions on how to perform a piece of music as intended.
• Soprano: a register of high pitches. In vocals, soprano refers to the highest register of women's voices.
• Staccato: playing a note with an intentionally short duration, giving a harsher, hacked sound.
• Staff: a set of lines used to display notes for one instrument and, if necessary, differentiate pitches quickly at sight. The position of pitches is set by a clef at the beginning of the staff. There can be only one clef for a single staff at the same time. If an extended range and/or multiple clefs are required, multiple staves can be bracketed to form a system.
• Suspension: to modify a chord by replacing its third with a second or fourth.
• Syncope: to intentionally put a delay between two beats.
• System: a group of two or more staves (singular: staff) for notation of instructions for one instrument.

T

• Time: usually refers to the number of beats in a measure, or the smallest number of quarter notes which fits into either one or two measures:
  • triple time: 3 beats - e.g. 3/4, 3/8, 6/4, 9/8
  • quadruple time: 4 beats - e.g. 4/4, 8/4, 12/8
  • quintuple time: 5 beats - e.g. 5/4, 5/8, 15/8
  • septuple time: 7 beats - e.g. 7/4, 7/8
  • and so on.
• Time signature: a symbol signifying the rhythmic composition of the music following it until either the piece of music ends or a new time signature shows up. Generally consists of two numbers stacked onto each other:
  • the lower number designates a particular note value. It is always a power of 2, most commonly 4 or 8.
  • the upper number designates how many notes of this value fit into one measure.
  • Common Time signatures may also be abbreviated with a letter C (4/4, "common time") or a C with a vertical slash (2/2, "cut time") instead of two numbers.
• Tone:
  • a) a particular pitch, played for a certain duration.
  • b) two semitones, see whole tone.
• Tonic: the pitch/tone which a harmony or melody "rests" on, and always returns back to; the tonic is always the first degree of a scale.
• Tremolo: playing a longer note by playing multiple very short notes of the same pitch in very fast succession.

UVW

• Verse: a repeated part of a song with a consistent rhythmic and harmonic motif but varying lyrics.
• Vibrato: a constant, pulsating change of volume or pitch.
• Vocals: human vocalization (speech, singing etc.) used in a musical context.
• Vocal range: the absolute range of pitches a particular human voice can perform.
• Whole tone: an interval of two semitones.

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