Abm7 is Ab, Cb, Eb and Gb — with the flat seventh added.
It sounds smooth and unhurried. The workhorse of the family, and the chord soul, funk and jazz comp on more than any other.
Pre-dominant — the ii of a major key, and a tonic in its own right.
Also written Abmin7, Ab-7 or Ab minor 7.
Abm7 is the ii of G♭ major: it leads to the dominant a fourth higher. ii–Vs can be chained so each dominant leads to the next ii, and each minor chord’s seventh falls a half step to the next dominant’s third.
Listen for: One line walks down a half step per chord through the whole chain, and holds on the last as the major seventh.
Abm7 has exactly the notes of B6. Hold the shape and put the key’s root under it, and the vi chord becomes the I. That is why the vi can stand in for the home chord.
Listen for: Only the bass moves, up a minor third. The four notes above it never change.
Abm7 is the vi of the basic turnaround in B major. In jazz it is usually replaced by an altered dominant on the same root.
When a minor ii–V lands on Abm7 and the chord lasts two bars, the second bar can turn it into Abm6 or a minor-major seventh, melody permitting.
In which keys. Every note of Abm7 belongs to C# minor, Eb minor, E major, F# major, Ab minor and B major.
Every note of Abm7 is in Ab minor pentatonic, Ab blues, Ab natural minor, Ab dorian and Ab phrygian.
Each of those is a page: the scale across the neck, and the chords it harmonises into — which is where Abm7 sits in it. Every scale.
Change one note of Abm7 and you have (drop the flat seventh), (the flat seventh becomes the sixth), (the fifth becomes the flat fifth), (add the ninth), (the flat seventh becomes the major seventh) or (the flat seventh becomes the ninth).
Abm7 is a minor chord — root, minor third, fifth. Minor chords on every root.
The common shapes and the derived voicings come from different places, and both are explained in how this site is built.
Shows each chord the way this style would voice it, and marks which of its alternatives belong to the idiom.