A Minor 6th
m6
0 - 3 - 7 - 9Minor + major 6th
About A Minor 6th
A minor sixth adds an F♯ to A minor — A, C, E, F♯ — and the result is a chord that sounds neither minor nor major but distinctly old. It belongs to swing, to musette, and to the kind of songwriting that predates rock, and on guitar it sits under the hand more easily than its rarity suggests.
The notes
A, C, E, F♯. The F♯ is a major sixth above the root, and against the minor third it produces the chord’s characteristic tension — bright and dark in the same breath.
The same four notes read from F♯ give F♯ half-diminished, which is why Am6 substitutes for that chord in jazz. One grip, two names, depending on the bass.
On the fretboard
The open shape modifies A minor by adding the F♯ on the high E string at the second fret. Nothing else moves, which makes it one of the cheapest four-note chords available.
A fuller version at the fifth fret with the root on the low E is the movable form, and it is what gypsy jazz uses — that idiom leans on minor sixths the way blues leans on dominants.
The open version has one quirk worth knowing: the F♯ on the top string sits above the C, so the sixth is the highest note in the chord. That placement is what makes it sound wistful rather than merely unusual — buried in the middle it barely registers.
Where it shows up
As a tonic in A minor in swing and musette, where the sixth is the default rather than an ornament. It also appears as the ii of G major in older popular song.
In jazz its main role is as a rootless dominant: Am6 over a D bass gives D9, which is why the chord turns up in places where no minor harmony is written at all.