Our glossaries so far have set out to define terms related to distribution, recording, streaming, and more, but we’ve yet to tackle what may be the most useful set of terms for musicians—actual music terms. Music theory can sometimes feel confusing and complicated, so we took some of its most important words and attempted to simplify things as much as possible. Understanding these terms thoroughly should help you communicate your own ideas to other musicians, or just pick up what fellow players, producers, and arrangers are putting down.

Beat and Bar/Measure: A beat is a single rhythmic unit of measurement in music. A measure or bar is a section of a piece of music that contains a specific number of beats, depending on the piece’s time signature, which is represented by what looks like a fraction. The bottom number identifies a certain kind of note; the top number specifies how many of those notes there are in each measure. For instance, in 4/4 time, there are four quarter-note beats per measure, in 3/4 time, there are three quarter-note beats per measure, and so on.

Chord: A chord occurs when multiple tones are played at once. For example, to play a G major chord on the piano, you’d press down a G key (the root, in this case), a B key (the third note in the key of G), and a D key (the fifth note in the key of G). When these notes ring out simultaneously, it creates the G major chord. There are many different types of chords, and the above example isn’t the formula for all of them. But if you are playing multiple notes on your instrument at the same time, you’re playing a chord.

Coda: A coda is a concluding section of a piece of music, and is typically separate in form from what came before it. It is independent of the verse, chorus, and bridge structures that make up the rest of the song. You know the part at the end of Fleetwood Mac’s “The Chain” when it gets quiet for a brief moment, and then the cool bass line comes in, and then the band totally cuts loose? That’s a coda.

Crescendo: A crescendo is simply a progressive increase in volume. To return to the example of the coda of “The Chain”—the beginning of the song’s coda, which gradually ascends in volume from very quiet to very loud, is also a great example of a crescendo. It’s a useful term to whip out if you need to clearly describe how you want a segment of a song—or even the whole song—to build in intensity.

Harmony: A harmony is when multiple tones from multiple sources come together simultaneously, in a pleasing way. When you play all the notes of a chord, you’re creating a type of harmony. The strumming of notes on a guitar can create a harmony; an orchestra of instruments playing together creates a harmony; and two or more voices singing together can create a harmony. Dolly Parton and Kenny Rogers run a master class on the last example with “Islands in the Stream.”

Flat/Sharp: Flats and sharps are semitone (or half-step) movements in pitch. Flat means "lower in pitch by a semitone," while sharp means "higher in pitch by a semitone." For example, C flat is a C lowered in pitch by a half-step. Often, you’ll hear people comment on a musician being sharp or flat—what they mean, essentially, is that they’ve hit a note outside the key they’re supposed to be performing in. But many keys contain sharps and flats. The keys of C major and A minor are the only ones without any.

Key: Key denotes the major or minor scale in which a piece of music operates, and thus, the notes that belong in it. A composer may choose to use "accidentals"—flat or sharp notes outside the song's overall key that are applied to that note for only the bar where they are marked.

Major/minor: Perhaps the most important distinction to make between major and minor keys is that major keys generally sound upbeat, and minor keys generally have a melancholy tinge to them. You can hear this difference in an example as small as individual chords—an A major chord sounds radically different than an A minor chord. Major keys use major scales and minor keys use minor scales, which are determined by their patterns of half and whole steps.

Melody: A melody is, in its simplest definition, a musical succession that combines pitch and rhythm to create something listeners perceive as cohesive—sometimes casually referred to as the tune. The Beatles were famous for the innovative pop melodies they crafted. The rise and fall, bounce, pace, and pitch of Paul McCartney’s voice on “Eleanor Rigby” are all factors in the creation of the song’s vocal melody.

Pitch: Pitch is the frequency of a sound—how high or low it is in relation to other sounds. A high frequency, produced by rapid vibration, creates a high pitch; a low frequency, produced by slow vibration, creates a low pitch. The chromatic scale contains 12 musical pitches.

Scale: As noted in our description of major and minor keys, scales are patterns of half and whole steps that create sequences of notes from the 12 pitches. A scale can include any number and combination of these pitches.

Solo: A solo is a segment of music that is played by a single musician, either by themselves or with a small amount of support accompaniment. Eddie Hazel’s astounding guitar performance on Funkadelic’s “Maggot Brain,” for example, is a solo.

Tempo: The pace of a piece of music is known as its tempo. Tempo can be measured by beats per minute, or bpm; classical music tempos are described by a set of terms ranging from larghissimo (very slow) to andante (a moderate speed) to prestissimo (very fast).

Timbre: While pitch may denote the exact frequency of a sound, many different instruments can produce the same pitch. To describe a sound further, the quality of its timbre is invoked; timbre is also sometimes known as the tone color of a sound. A brassy timbre sounds much different than a reedy one. If you play a C note on a bright piano, it will sound distinct from a C played on a more dull piano, or an organ, or a bass guitar. And a final note: It’s pronounced tam-ber.

—Matt Williams