The A♭ 7♭5♯9 chord is a five-note chord made up of A♭, C, E♭♭, G♭, and B. It is built from a root, major third, diminished fifth, minor seventh, and augmented ninth.
Construction
A♭ 7♭5♯9 = Root + Major 3rd + Diminished 5th + Minor 7th + Minor 3rd = A♭ · C · E♭♭ · G♭ · B
| Note | Interval | Degree |
|---|---|---|
| A♭ | Root | 1 |
| C | Major 3rd | 3 |
| E♭♭ | Diminished 5th | ♭5 |
| G♭ | Minor 7th | ♭7 |
| B | Minor 3rd | ♭3 |
Key Signature
A chord has no key signature of its own, but the A♭ 7♭5♯9 is the tonic (I) chord of Ab Major, whose key signature has 4 flats (B♭, E♭, A♭, D♭).
B♭E♭A♭D♭
Order of flats
Flats are added in a fixed order — the reverse of the sharp order. Each new flat key adds the next flat on the list.
B♭E♭A♭D♭G♭C♭F♭
Mnemonic: Battle Ends And Down Goes Charles’ Father
Chords in the Key of A♭ Major
These are the triads built on each degree of the A♭ major scale:
A♭ 7♭5♯9 — Frequently Asked Questions
What is the A♭ 7♭5♯9 chord on piano?
The A♭ 7♭5♯9 chord contains the notes A♭ – C – E♭♭ – G♭ – B. On piano, play these notes together to sound the chord.
What notes are in the Ab 7♭5♯9 chord?
The Ab 7♭5♯9 chord (Ab7♭5♯9) contains 5 notes: Ab, C, D, Gb, B. Formula: R-M3-d5-m7-A9.
How is Ab7♭5♯9 used in music?
Ab7♭5♯9 is used in jazz, fusion, and contemporary music to add harmonic color. It appears as a dominant or tonic chord depending on context.
What is the scale degree formula for Ab7♭5♯9?
Ab7♭5♯9 uses scale degrees 1-3-b5-b7-#9, giving it its distinctive sound.