An old photograph that still smells of summer.
The Chord
Sixth chords take a triad and add the sixth degree of the scale rather than a seventh. The added note sits a whole step above the fifth, colouring the chord without demanding resolution the way a seventh does. A major sixth stacks the sixth over a major triad — on C that is C, E, G, A. A minor sixth adds a major sixth to a minor triad — C, E♭, G, A. In both cases the extra note is the same pitch; what changes is the third beneath it.
Because the sixth is a consonant, folded-in colour rather than a tension, sixth chords feel finished. They are triads wearing a little extra warmth, stable enough to end a piece on yet richer than a bare triad. The minor sixth is the subtler of the two, its major sixth glinting unexpectedly against the minor body.
Structure
| Attribute | Value |
|---|---|
| Formula | major 6: 1 3 5 6 · minor 6: 1 ♭3 5 6 |
| Notes (on C) | C6: C E G A · Cm6: C E♭ G A |
| Symbol | C6 / Cm6 |
| Quality | Sweet, vintage, resolved but coloured |
Character
Sixth chords sound nostalgic — sweet, gentle, and slightly old-fashioned in the best way. The major sixth has a sunny, cocktail-hour glow, the sound of big-band endings and doo-wop cadences. The minor sixth is more intriguing, a soft melancholy with an unexpected brightness that borders on the mysterious. Both feel settled yet dressed up, resolution with a ribbon on it.
In Practice
The major sixth was the definitive final chord of swing-era arrangements, a tonic that ends a tune with warmth instead of a plain triad. In jazz and pop it substitutes for the tonic wherever a softer, richer landing is wanted. The minor sixth doubles as a colourful minor tonic and, thanks to its structure, as a subtle dominant flavour in the right voicing. Sixth chords are the Major Triad and Minor Triad given a coat of colour, cousins to the Major Seventh.