Chord · Altered Dom.

A7♭5♯9 — A Altered ♭5♯9

A7♭5♯9 is the A altered ♭5♯9 chord. It is built on the root A with major 3rd (C♯), diminished 5th (E♭), minor 7th (G) and augmented 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♭5♯9.

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

On the keyboard

A7♭5♯9 on the piano keyboard: A C♯ E♭ G B♯AC♯E♭GB♯

The notes of A7♭5♯9

DegreeNoteInterval from the rootPitch
1ArootA3
3C♯major 3rdC♯4
♭5E♭diminished 5thE♭4
♭7Gminor 7thG4
♯9B♯augmented 9thB♯4

Other altered dom. on A

Altered ♭5♯9 chords on every root

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