Music Theory Glossary

Bright, happy, and stable. The most common chord quality in Western music, found in countless pop, rock, and folk songs. Its formula is 1 – 3 – 5. For example, C is a major chord.

A Major chord is built using the formula 1 – 3 – 5. For example, C contains the notes C, E, G. Each root note produces a major chord with the same interval pattern but different note names.

Same notes with raised 3rd to 4th. The Major chord formula is 1 – 3 – 5, while the Sus4 chord has a different interval structure.

Dark, somber, and introspective. Often used to convey sadness, tension, or depth in ballads, rock, and jazz. Its formula is 1 – ♭3 – 5. For example, Am is a minor chord.

A Minor chord is built using the formula 1 – ♭3 – 5. For example, Am contains the notes A, C, E. Each root note produces a minor chord with the same interval pattern but different note names.

Parallel major (raised 3rd). The Minor chord formula is 1 – ♭3 – 5, while the Major chord has a different interval structure.

Bluesy, tension-filled sound that wants to resolve. The backbone of blues, jazz, and many rock progressions. Its formula is 1 – 3 – 5 – ♭7. For example, G7 is a 7th chord.

A 7th chord is built using the formula 1 – 3 – 5 – ♭7. For example, G7 contains the notes G, B, D, F. Each root note produces a 7th chord with the same interval pattern but different note names.

Same chord with natural 7th instead of flat 7th. The 7th chord formula is 1 – 3 – 5 – ♭7, while the Maj7 chord has a different interval structure.

Warm, lush, and dreamy. A staple of jazz, bossa nova, and sophisticated pop arrangements. Its formula is 1 – 3 – 5 – 7. For example, Cmaj7 is a maj7 chord.

A Maj7 chord is built using the formula 1 – 3 – 5 – 7. For example, Cmaj7 contains the notes C, E, G, B. Each root note produces a maj7 chord with the same interval pattern but different note names.

Lower the 7th one semitone. The Maj7 chord formula is 1 – 3 – 5 – 7, while the 7th chord has a different interval structure.

Smooth, mellow, and versatile. Common in jazz, R&B, neo-soul, and funk for a relaxed, groovy feel. Its formula is 1 – ♭3 – 5 – ♭7. For example, Dm7 is a min7 chord.

A Min7 chord is built using the formula 1 – ♭3 – 5 – ♭7. For example, Dm7 contains the notes D, F, A, C. Each root note produces a min7 chord with the same interval pattern but different note names.

Major triad with flat 7th. The Min7 chord formula is 1 – ♭3 – 5 – ♭7, while the 7th chord has a different interval structure.

Tense, unstable, and suspenseful. Often used as a passing chord to create motion between stable chords. Its formula is 1 – ♭3 – ♭5. For example, Bdim is a dim chord.

A Dim chord is built using the formula 1 – ♭3 – ♭5. For example, Bdim contains the notes B, D, F. Each root note produces a dim chord with the same interval pattern but different note names.

Add a diminished 7th for symmetrical beauty. The Dim chord formula is 1 – ♭3 – ♭5, while the Dim7 chord has a different interval structure.

Dark and suspenseful with symmetrical structure. Common in dramatic transitions in jazz and classical music. Its formula is 1 – ♭3 – ♭5 – ♭♭7. For example, Cdim7 is a dim7 chord.

A Dim7 chord is built using the formula 1 – ♭3 – ♭5 – ♭♭7. For example, Cdim7 contains the notes C, D#, F#, A. Each root note produces a dim7 chord with the same interval pattern but different note names.

Diminished triad plus diminished 7th. The Dim7 chord formula is 1 – ♭3 – ♭5 – ♭♭7, while the Dim chord has a different interval structure.

Dreamy, floating, and unresolved. Creates a sense of anticipation, often used to transition to the next chord. Its formula is 1 – 3 – ♯5. For example, Caug is a aug chord.

A Aug chord is built using the formula 1 – 3 – ♯5. For example, Caug contains the notes C, E, G#. Each root note produces a aug chord with the same interval pattern but different note names.

Raise the 5th one semitone from major. The Aug chord formula is 1 – 3 – ♯5, while the Major chord has a different interval structure.

Tense and restless with an augmented triad under a dominant seventh. Bluesy edge with floating color, common in jazz and Latin styles. Its formula is 1 – 3 – ♯5 – ♭7. For example, Caug7 is a aug7 chord.

A Aug7 chord is built using the formula 1 – 3 – ♯5 – ♭7. For example, Caug7 contains the notes C, E, G#, A#. Each root note produces a aug7 chord with the same interval pattern but different note names.

Augmented triad plus flat 7th. The Aug7 chord formula is 1 – 3 – ♯5 – ♭7, while the Aug chord has a different interval structure.

Open, airy, and ambiguous — neither major nor minor. Popular in rock ballads and atmospheric music. Its formula is 1 – 2 – 5. For example, Dsus2 is a sus2 chord.

A Sus2 chord is built using the formula 1 – 2 – 5. For example, Dsus2 contains the notes D, E, A. Each root note produces a sus2 chord with the same interval pattern but different note names.

Same concept — raise the 2nd to 4th. The Sus2 chord formula is 1 – 2 – 5, while the Sus4 chord has a different interval structure.

Tense and expectant, wanting to resolve back to major. Widely used in rock, folk, and worship music. Its formula is 1 – 4 – 5. For example, Dsus4 is a sus4 chord.

A Sus4 chord is built using the formula 1 – 4 – 5. For example, Dsus4 contains the notes D, G, A. Each root note produces a sus4 chord with the same interval pattern but different note names.

Same concept — lower the 4th to 2nd. The Sus4 chord formula is 1 – 4 – 5, while the Sus2 chord has a different interval structure.

Sparkling and colorful with an extra note layered on a major triad. Adds warmth to pop and rock arrangements. Its formula is 1 – 3 – 5 – 9. For example, Cadd9 is a add9 chord.

A Add9 chord is built using the formula 1 – 3 – 5 – 9. For example, Cadd9 contains the notes C, E, G, D. Each root note produces a add9 chord with the same interval pattern but different note names.

Major triad plus the 9th color tone. The Add9 chord formula is 1 – 3 – 5 – 9, while the Major chord has a different interval structure.

Rich, funky, and bluesy. A dominant 7th with added color, essential in funk, jazz, and R&B. Its formula is 1 – 3 – 5 – ♭7 – 9. For example, C9 is a 9th chord.

A 9th chord is built using the formula 1 – 3 – 5 – ♭7 – 9. For example, C9 contains the notes C, E, G, A#, D. Each root note produces a 9th chord with the same interval pattern but different note names.

The 9th extends the dominant 7th. The 9th chord formula is 1 – 3 – 5 – ♭7 – 9, while the 7th chord has a different interval structure.

Dark and tense with a bittersweet quality. Commonly used as the ii chord in minor ii-V-i jazz progressions. Its formula is 1 – ♭3 – ♭5 – ♭7. For example, Bm7b5 is a m7b5 chord.

A m7b5 chord is built using the formula 1 – ♭3 – ♭5 – ♭7. For example, Bm7b5 contains the notes B, D, F, A. Each root note produces a m7b5 chord with the same interval pattern but different note names.

Full diminished — lower the 7th one more. The m7b5 chord formula is 1 – ♭3 – ♭5 – ♭7, while the Dim7 chord has a different interval structure.

Mysterious and jazzy with a minor triad topped by a major seventh. A signature sound of film noir, spy themes, and sophisticated jazz ballads. Its formula is 1 – ♭3 – 5 – 7. For example, CmMaj7 is a mmaj7 chord.

A mMaj7 chord is built using the formula 1 – ♭3 – 5 – 7. For example, CmMaj7 contains the notes C, D#, G, B. Each root note produces a mmaj7 chord with the same interval pattern but different note names.

Minor 7th with natural 7th vs flat 7th. The mMaj7 chord formula is 1 – ♭3 – 5 – 7, while the Min7 chord has a different interval structure.

Haunting and dark with a diminished triad under a major seventh. Tense and unresolved, used in dramatic cinematic scoring and advanced jazz harmony. Its formula is 1 – ♭3 – ♭5 – 7. For example, CdimMaj7 is a dimmaj7 chord.

A dimMaj7 chord is built using the formula 1 – ♭3 – ♭5 – 7. For example, CdimMaj7 contains the notes C, D#, F#, B. Each root note produces a dimmaj7 chord with the same interval pattern but different note names.

Diminished triad plus major 7th. The dimMaj7 chord formula is 1 – ♭3 – ♭5 – 7, while the Dim chord has a different interval structure.

Luxurious, expansive, and ethereal. Adds rich harmonic color to jazz, neo-soul, and R&B ballads. Its formula is 1 – 3 – 5 – 7 – 9. For example, Cmaj9 is a maj9 chord.

A Maj9 chord is built using the formula 1 – 3 – 5 – 7 – 9. For example, Cmaj9 contains the notes C, E, G, B, D. Each root note produces a maj9 chord with the same interval pattern but different note names.

Extend maj7 with a 9th. The Maj9 chord formula is 1 – 3 – 5 – 7 – 9, while the Maj7 chord has a different interval structure.

Deep, soulful, and sophisticated. A minor 7th with added warmth, popular in jazz, R&B, and neo-soul. Its formula is 1 – ♭3 – 5 – ♭7 – 9. For example, Cm9 is a min9 chord.

A Min9 chord is built using the formula 1 – ♭3 – 5 – ♭7 – 9. For example, Cm9 contains the notes C, D#, G, A#, D. Each root note produces a min9 chord with the same interval pattern but different note names.

Extend min7 with a 9th. The Min9 chord formula is 1 – ♭3 – 5 – ♭7 – 9, while the Min7 chord has a different interval structure.

A power chord: just the root and fifth. The beginner rock sound — no third, so it is neither major nor minor. Its formula is 1 – 5. For example, C5 is a power chord.

A Power chord is built using the formula 1 – 5. For example, C5 contains the notes C, G. Each root note produces a power chord with the same interval pattern but different note names.

Add the third to make a major triad. The Power chord formula is 1 – 5, while the Major chord has a different interval structure.

A major triad with both the sixth and ninth. Sparkling jazz/pop color without a seventh — warmer than add9. Its formula is 1 – 3 – 5 – 6 – 9. For example, C69 is a 6/9 chord.

A 6/9 chord is built using the formula 1 – 3 – 5 – 6 – 9. For example, C69 contains the notes C, E, G, A, D. Each root note produces a 6/9 chord with the same interval pattern but different note names.

Drop the 6th for a simpler add9. The 6/9 chord formula is 1 – 3 – 5 – 6 – 9, while the Add9 chord has a different interval structure.

The Hendrix chord: a dominant 7th with a raised ninth. Gritty blues/rock tension that wants to resolve. Its formula is 1 – 3 – 5 – ♭7 – ♯9. For example, C7#9 is a 7♯9 chord.

A 7♯9 chord is built using the formula 1 – 3 – 5 – ♭7 – ♯9. For example, C7#9 contains the notes C, E, G, Bb, D#. Each root note produces a 7♯9 chord with the same interval pattern but different note names.

Drop the ♯9 for a plain dominant 7th. The 7♯9 chord formula is 1 – 3 – 5 – ♭7 – ♯9, while the 7th chord has a different interval structure.

A major 7th extended through the 9th to the 13th. Lush, advanced jazz color over a stable major foundation. Its formula is 1 – 3 – 5 – 7 – 9 – 13. For example, Cmaj13 is a maj13 chord.

A Maj13 chord is built using the formula 1 – 3 – 5 – 7 – 9 – 13. For example, Cmaj13 contains the notes C, E, G, B, D, A. Each root note produces a maj13 chord with the same interval pattern but different note names.

Drop the 13th for maj9. The Maj13 chord formula is 1 – 3 – 5 – 7 – 9 – 13, while the Maj9 chord has a different interval structure.

A major triad with an added sixth. Warm and complete — the same pitch-classes as a relative minor 7th, but the root decides. Its formula is 1 – 3 – 5 – 6. For example, C6 is a 6 chord.

A 6 chord is built using the formula 1 – 3 – 5 – 6. For example, C6 contains the notes C, E, G, A. Each root note produces a 6 chord with the same interval pattern but different note names.

Drop the 6th. The 6 chord formula is 1 – 3 – 5 – 6, while the Major chord has a different interval structure.

A minor triad with an added sixth. Darker than a 6, brighter than a min7 — 1 ♭3 6, with the fifth optional. Its formula is 1 – ♭3 – 5 – 6. For example, Cm6 is a min6 chord.

A Min6 chord is built using the formula 1 – ♭3 – 5 – 6. For example, Cm6 contains the notes C, Eb, G, A. Each root note produces a min6 chord with the same interval pattern but different note names.

Drop the 6th. The Min6 chord formula is 1 – ♭3 – 5 – 6, while the Minor chord has a different interval structure.

A dominant 7th with the 13th (the 6th, an octave up). Jazz/funk color that is not a 9th and not a maj13 — 1 3 13 ♭7. Its formula is 1 – 3 – 13 – ♭7. For example, C13 is a 13th chord.

A 13th chord is built using the formula 1 – 3 – 13 – ♭7. For example, C13 contains the notes C, E, A, Bb. Each root note produces a 13th chord with the same interval pattern but different note names.

Drop the 13th. The 13th chord formula is 1 – 3 – 13 – ♭7, while the 7th chord has a different interval structure.

A dominant 11th that omits the third: 1 9 11 ♭7. Not a 7sus4 — the 9th is preferred and the 3rd stays out. Its formula is 1 – 9 – 11 – ♭7. For example, C11 is a 11th chord.

A 11th chord is built using the formula 1 – 9 – 11 – ♭7. For example, C11 contains the notes C, D, F, Bb. Each root note produces a 11th chord with the same interval pattern but different note names.

Drop the 11th. The 11th chord formula is 1 – 9 – 11 – ♭7, while the 7th chord has a different interval structure.

A dominant 7th with the third replaced by a fourth. Suspended tension that is not a plain sus4 — keep 1 4 ♭7. Its formula is 1 – 4 – 5 – ♭7. For example, C7sus4 is a 7sus4 chord.

A 7sus4 chord is built using the formula 1 – 4 – 5 – ♭7. For example, C7sus4 contains the notes C, F, G, Bb. Each root note produces a 7sus4 chord with the same interval pattern but different note names.

Drop the ♭7. The 7sus4 chord formula is 1 – 4 – 5 – ♭7, while the Sus4 chord has a different interval structure.

A dominant 7th with a flattened ninth. Dark jazz/minor-key tension, next to 7♯9 — keep 1 3 ♭7 ♭9. Its formula is 1 – ♭9 – 3 – 5 – ♭7. For example, C7b9 is a 7♭9 chord.

A 7♭9 chord is built using the formula 1 – ♭9 – 3 – 5 – ♭7. For example, C7b9 contains the notes C, Db, E, G, Bb. Each root note produces a 7♭9 chord with the same interval pattern but different note names.

Drop the ♭9. The 7♭9 chord formula is 1 – ♭9 – 3 – 5 – ♭7, while the 7th chord has a different interval structure.

A secondary dominant is the V chord of a diatonic chord other than the tonic. In C major, A7 is the V of Dm (written V7/ii) and D7 is the V of G (written V7/V). It introduces a chromatic leading tone that creates a stronger pull toward its target chord without leaving the home key.

Use the form V/x (or V7/x), where x is the target chord. For example, V7/ii in C major is A7 resolving to Dm. The slash separates the applied dominant from its target, and the chord is built as if the target were a temporary tonic.

A tritone substitution replaces a dominant 7th chord with another dominant 7th whose root is a tritone (6 semitones) away. Db7 substitutes for G7 because both chords contain the same tritone interval (B and F). The 3rd of one chord becomes the 7th of the other, so they resolve identically to the same tonic. This technique is widely used in jazz to create smooth chromatic bass lines.

Both the original V7 and its tritone substitute share the same two guide tones — the 3rd and 7th that form the tritone responsible for the dominant's pull to the tonic. The other two notes (root and 5th) differ, which changes the bass motion, but the harmonic function is preserved. The result is a chromatically descending or ascending bass line with the same resolution.

The Neapolitan chord is a major triad built on the lowered second degree (♭II) of the scale. In C major or C minor it is D♭ major. It is used as a pre-dominant chord that resolves to V (or directly to I), creating a dramatic chromatic color rooted in classical and romantic cadences. The 'Neapolitan sixth' is the same chord in first inversion, which places the 3rd of the triad in the bass for a smooth stepwise descent to the dominant.

The Neapolitan chord most often resolves to the dominant (V). The ♭2 scale degree at the top of the chord moves down by semitone to the leading tone of the dominant, then resolves upward into V. In first inversion (Neapolitan sixth), the bass steps down from the 3rd of the triad to the dominant root, producing the smooth chromatic voice-leading that makes the device so effective in cadential contexts.

Modal interchange (or modal mixture) is the technique of borrowing chords from the parallel key while keeping the same tonic. In C major you might borrow Fm, A♭, B♭, or E♭ from C minor. These borrowed chords introduce chromatic notes from the parallel scale, creating emotional contrast — a sudden darkening or lift — without actually modulating to a new key. It is one of the most common ways songwriters add harmonic color in pop, rock, jazz, and film music.

The most common borrowed chords when borrowing from the parallel minor in a major key are the minor iv (Fm in C major), ♭VI (A♭), ♭VII (B♭), and ♭III (E♭). The minor iv is especially popular for its bittersweet color returning to I, while ♭VII–IV–I is the signature arena-rock progression. Each borrowed chord injects a single chromatic note from the parallel scale, which is why they sound colorful without feeling like a key change.

An altered chord is a dominant 7th whose 5th or 9th has been chromatically raised or lowered — ♭5, ♯5, ♭9, or ♯9. A dominant can carry several alterations at once (written G7alt). Because every altered tone lies outside the home scale and resolves by half step onto a chord tone of the tonic, altered dominants produce the strongest possible V→I pull. They are a staple of jazz ii–V–I progressions and fusion harmony.

The 'Hendrix chord' is a dominant 7th with a sharpened 9th (7♯9), most famously heard as E7♯9 in Jimi Hendrix's 'Purple Haze'. It contains the notes E, G♯, B, D, and G — stacking a major 3rd (G♯) and the ♯9 (enharmonic with a minor 3rd, G) on the same root. That simultaneous major-and-minor color is what gives the chord its biting, bluesy character and makes it a staple of blues-rock and funk.

Scale degrees are the numbered positions of notes within a scale, each with a traditional name: Tonic (1st), Supertonic (2nd), Mediant (3rd), Subdominant (4th), Dominant (5th), Submediant (6th), and Leading Tone (7th). Each degree naturally produces a specific chord quality — major triads on I, IV, and V; minor triads on ii, iii, and vi; and a diminished triad on vii°.

The most common chord progressions include I-V-vi-IV (pop ballad), ii-V-I (jazz), I-IV-V (rock/blues), I-IV-V-I (classical cadence), and the Pachelbel Canon progression (I-V-vi-iii-IV-I-IV-V). These progressions form the harmonic backbone of most Western popular music across genres.

Chord substitution replaces one chord with another that serves a similar harmonic function. The main types are diatonic substitution (swapping chords that share notes within the same key, like C and Am), tritone substitution (replacing a dominant 7th with another dominant 7th a tritone away, like G7 and Db7), secondary dominants (borrowing the V chord of a non-tonic chord), and borrowed chords (taking chords from a parallel key). Substitutions add harmonic variety while preserving the overall progression's function.

Start with diatonic substitutions (the safest), then experiment with tritone substitutions on dominant 7th chords. The Progression Substitution Planner and Chord Substitution Finder tools list replacements by function. The Progression Library lets you save and practice substituted progressions at different tempos with looping playback.

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