Reference

Chord library

Every chord is just a stack of intervals over a root. Learn the formulas and you can build any chord on any note without a chart.

Triads (three-note chords)

ChordSymbolFormulaExample (C root)
MajorC1 3 5C E G
MinorCm1 ♭3 5C E♭ G
Diminished1 ♭3 ♭5C E♭ G♭
AugmentedC+1 3 ♯5C E G♯
Suspended 2Csus21 2 5C D G
Suspended 4Csus41 4 5C F G

C major triad

A minor triad

Seventh chords

ChordSymbolFormulaExample (C root)
Major 7Cmaj71 3 5 7C E G B
Dominant 7C71 3 5 ♭7C E G B♭
Minor 7Cm71 ♭3 5 ♭7C E♭ G B♭
Minor 7 ♭5 (half-dim)Cm7♭51 ♭3 ♭5 ♭7C E♭ G♭ B♭
Diminished 7C°71 ♭3 ♭5 ♭♭7C E♭ G♭ B♭♭ (A)
Minor-major 7CmMaj71 ♭3 5 7C E♭ G B

Cmaj7

G7 (dominant)

Am7

Extended chords (9, 11, 13)

Stack thirds beyond the 7th to get the 9th, 11th, and 13th. These tones add color without changing the chord's basic function.

ChordSymbolFormula
Major 9Cmaj91 3 5 7 9
Dominant 9C91 3 5 ♭7 9
Minor 9Cm91 ♭3 5 ♭7 9
Add 9Cadd91 3 5 9
Dominant 11C111 3 5 ♭7 9 11
Dominant 13C131 3 5 ♭7 9 11 13
6thC61 3 5 6
Minor 6Cm61 ♭3 5 6

Altered dominants

Dominant chords with sharpened or flattened 5ths and 9ths — the "tension" sounds in jazz and blues.

ChordSymbolFormula
Dom 7 ♭9C7♭91 3 5 ♭7 ♭9
Dom 7 ♯9C7♯91 3 5 ♭7 ♯9
Dom 7 ♯5 (aug)C7♯51 3 ♯5 ♭7
Dom 7 ♭5C7♭51 3 ♭5 ♭7
Dom 7 altC7alt1 3 ♭7 + any altered 5/9
The single biggest unlock: stop memorising chord shapes. Memorise the formula and the root, and let the shape come from that. You'll end up with chord vocabulary that survives any key change.