Music Theory Glossary

chord

Three or more notes played together to create harmony.

major triad

Three notes built from a root, major third, and perfect fifth. The foundation of most Western harmony.

minor triad

Three notes built from a root, minor third, and perfect fifth. A darker, sadder sound than the major triad.

major chord

Three notes with a bright, stable, happy quality.

minor chord

Three notes with a darker, more emotional quality.

major seventh chord

Warm, jazzy, dreamy. The major triad plus a major seventh.

minor seventh chord

Smooth, mellow. Common in jazz and R&B.

dominant seventh chord

Bluesy tension. Wants to resolve down a fifth.

diminished chord

Tense and unstable. Built from two minor thirds.

diminished seventh chord

Symmetrical and tense. Every note is a minor third apart.

augmented chord

Mysterious, unsettled. Built from two major thirds.

suspended fourth chord

Neither major nor minor. The fourth replaces the third.

suspended second chord

Open and ambiguous. The second replaces the third.

C major seventh

C-E-G-B. A major triad with a major seventh on top. Warm, dreamy, jazzy.

C dominant seventh

C-E-G-B♭. A major triad with a minor seventh. Bluesy tension that pulls strongly toward F.

half step

The smallest distance between two notes on the piano — one key to the very next key.

whole step

Two half steps. The distance between most adjacent notes in the major scale.

minor third

Three semitones above the root. The defining sound of minor chords — darker and more emotional.

major third

Four semitones above the root. Bright and stable — the defining sound of major chords.

perfect fourth

Five semitones above the root. Stable and open-sounding.

tritone

Six semitones — exactly splitting the octave in half. The most dissonant interval, wants to resolve.

perfect fifth

Seven semitones above the root. Open and consonant — present in almost every chord.

octave

The same note name one register higher. Complete consonance.

perfect unison

Same note. No distance.

minor second

One half step. Tense and dissonant.

major second

One whole step. A common melodic step.

minor third

The sound of a minor chord. Darker, sadder.

major third

The sound of a major chord. Bright, happy.

perfect fourth

Stable and open. The plagal sound.

tritone

Three whole steps. Maximum instability.

perfect fifth

The most consonant interval after the octave. Pure and open.

minor sixth

Expressive and wide. Inverted major third.

major sixth

Warm and sweet. Inverted minor third.

minor seventh

Bluesy tension. Wants to resolve down.

major seventh

Dreamy, jazzy tension. One half step from the octave.

octave

Same note, one octave higher. Complete consonance.

major scale

Bright and stable. Built with the pattern whole-whole-half-whole-whole-whole-half.

natural minor scale

Darker and more emotional. Built with the pattern whole-half-whole-whole-half-whole-whole.

natural minor scale

Darker and more emotional. Built with the pattern whole-half-whole-whole-half-whole-whole.

major pentatonic scale

Five notes (degrees 1-2-3-5-6) with an open, flexible sound used across many styles.

minor pentatonic scale

Five-note minor scale (1-♭3-4-5-♭7) with a dark, soulful sound — the foundation of blues improvisation.

blues scale

A soulful scale with extra color and tension, common in blues, rock, and jazz.

chromatic scale

All 12 notes within an octave, each a half step apart.

Ionian (major)

The natural major scale. Bright and stable — the most familiar sound in Western music.

Dorian

Minor with a raised 6th. Jazzy and soulful — used heavily in jazz, funk, and rock.

Phrygian

Minor with a lowered 2nd. Dark and Spanish-flavored — used in flamenco and metal.

Lydian

Major with a raised 4th. Dreamy and floating — favored in film scores.

Mixolydian

Major with a lowered 7th. Bluesy and confident — the sound of blues and classic rock.

Aeolian (natural minor)

The natural minor scale. Darker and more emotional than major.

Locrian

Diminished with a lowered 2nd and 5th. Extremely unstable — rarely used as a tonal center.

I — major tonic

Home base. The key center everything revolves around.

ii — minor supertonic

Often leads to V. A common pre-dominant chord.

iii — minor mediant

Shares notes with I and V. A softer, connective chord.

IV — major subdominant

Strong pull toward home. Classic plagal cadence to I.

V — major dominant

The strongest pull back to I. Creates tension that wants to resolve.

vi — minor submediant

The relative minor. Starting point for many emotional progressions.

vii° — diminished leading tone

Tense and unstable. Pulls strongly up to I.

vii° — diminished leading tone

Tense and unstable. Pulls strongly up to I.

i — minor tonic

Home base in a minor key.

iv — minor subdominant

Borrowed from the parallel minor. A darker, more poignant pull toward I.

♭VII — borrowed subtonic

Borrowed from the parallel minor. A major chord a whole step below tonic — adds a rock or modal flavour.

root — tonic

The home note. Every other degree is measured from here.

2 — second

One whole step above the root. Common melodic step.

♭3 — flat third

Three half steps above the root. The note that makes minor chords dark.

3 — third

Four half steps above the root. The note that makes major chords bright.

4 — fourth

Five half steps above the root. Stable and open.

5 — fifth

Seven half steps above the root. The most stable interval after the octave.

6 — sixth

Nine half steps above the root. Warm and bright.

♭7 — flat seventh

Ten half steps above the root. The blues note — gives dominant seventh chords their pull.

7 — major seventh

Eleven half steps above the root. The leading tone — wants to resolve up to the octave.

Cadence

A harmonic ending — the chords used to close a musical phrase. Cadences define whether a phrase feels finished, unfinished, or surprising.

Authentic cadence

V→I. Strong and final — the most conclusive way to end a phrase. Like a period at the end of a sentence.

Half cadence

Any chord→V. Ends on the dominant — unfinished, like a question mark.

Plagal cadence

IV→I. Warm and gentle — called the "Amen cadence" because it ends countless hymns.

Deceptive cadence

V→vi. Expects I but gets vi instead — a surprise that creates continuation rather than closure.

Piano

Soft.

Mezzo-piano

Moderately soft.

Mezzo-forte

Moderately loud.

Forte

Loud.

Fortissimo

Very loud.

Crescendo

Gradually getting louder.

Decrescendo

Gradually getting softer.

Tempo

The speed of the beat, measured in BPM (beats per minute). Affects the mood and energy of music.

BPM

Beats per minute — the unit used to measure tempo. 60 BPM = one beat per second.

Adagio

Slow and expressive. 66–75 BPM.

Andante

Walking pace. 76–89 BPM.

Moderato

Moderate speed. 90–109 BPM.

Allegro

Fast and lively. 110–131 BPM.

Vivace

Very fast and vibrant. 132–159 BPM.

Presto

Extremely fast. 160–199 BPM.

time signature

The symbol at the start of a piece telling you how many beats are in each measure and which note value gets one beat.

Common Time

4 beats per measure, quarter note gets one beat.

Waltz Time

3 beats per measure, quarter note gets one beat.

Compound Duple

2 groups of 3 eighth notes per measure.

rhythm

The pattern of long and short notes and silences that gives music its movement and groove.

whole note

Held for a full measure in 4/4. Four beats.

half note

Half the duration of a whole note. Two beats.

quarter note

The basic beat in most time signatures. One beat.

eighth note

Half a beat. Two per beat, often beamed together.

musical note

A single sound with a defined pitch and duration — the building block of melody.

musical notes

Sounds with defined pitch and duration — the building blocks of melody.

C

The first white key in each octave. Home base of C major — the most common starting key for beginners.

D

A whole step above C. The second degree of the C major scale.

E

A major third above C. The third degree of the C major scale — gives major chords their brightness.

F

A perfect fourth above C. The fourth degree of the C major scale.

G

A perfect fifth above C. The most consonant interval above the root after the octave.

A

A major sixth above C. The sixth degree of C major — also the root of A minor, its relative minor.

B

A major seventh above C. One half step below the octave — the leading tone in C major.

E♭

One half step below E. Moving the E in a C major chord down to E♭ turns it into C minor.

B♭

One half step below B. The ♭7 of a C dominant seventh chord — creates its characteristic bluesy pull.

C#

One half step above C. The black key between C and D — also called D♭.

F#

One half step above F. The black key between F and G — also called G♭. Forms a tritone with C.

D♭

One half step below D. The same key as C# — two names, same note (enharmonic equivalent).

C3

C in the third octave. One octave below middle C (C4). Vibrates at approximately 130 Hz.

C4 — middle C

Middle C. The most referenced note in music — near the center of the piano, vibrating at 261 Hz.

musical key

A set of notes centered on one tonic, giving music its harmonic home and characteristic sound.

musical keys

Sets of notes each centered on a different tonic, forming the harmonic backbone of a piece.