A7♭9
A 7th Flat 9 · 4 fingerings
Flattening the ninth of a dominant chord gives A7♭9 a dark, tense edge that pulls hard toward resolution — especially into a minor chord. It's essential jazz vocabulary for the V chord in a minor key, and it shares its notes with a diminished seventh a semitone up, which is why diminished shapes work so well over it.
A7♭9 · position 1
A7♭9 · position 2 · fret 5
A7♭9 · position 3 · fret 6
A7♭9 · position 4 · fret 11