Chord · Altered Dom.

A7♭9 — A Dominant 7th ♭9

A7♭9 is the A dominant 7th ♭9 chord. It is built on the root A with major 3rd (C♯), perfect 5th (E), minor 7th (G) and minor 9th (B♭) above it — the formula 1 3 5 ♭7 ♭9, sounding the notes A C♯ E G B♭. On the piano it sits at A (octave 3) and above in the library's voicing; the same 5 notes in any octave are still A7♭9.

Root
A
Quality
Dominant 7th ♭9
Formula
1 3 5 ♭7 ♭9
Notes
A C♯ E G B♭

On the keyboard

A7♭9 on the piano keyboard: A C♯ E G B♭AC♯EGB♭

The notes of A7♭9

DegreeNoteInterval from the rootPitch
1ArootA3
3C♯major 3rdC♯4
5Eperfect 5thE4
♭7Gminor 7thG4
♭9B♭minor 9thB♭4

Other altered dom. on A

Dominant 7th ♭9 chords on every root

Part of the chord reference. See also the scales and the keys.