A♭9♯11: G♯/A♭ Dominant 9th Sharp 11th Piano Chord

Construction

A♭ 9♯11 = Root + Major 3rd + Perfect 5th + Minor 7th + Major 2nd + Diminished 5th = A♭, C, E♭, G♭, B♭, D

Note	Interval	Degree
A♭	Root	1
C	Major 3rd	3
E♭	Perfect 5th	5
G♭	Minor 7th	♭7
B♭	Major 2nd	9
D	Diminished 5th	♭5

Key Signature

A chord has no key signature of its own, but the A♭ 9♯11 is the tonic (I) chord of A♭ 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 A♭ Major:

I — A♭ Major (major)

Degree	Numeral	Chord	Quality
1	I	A♭ Major	Major
2	ii	B♭ Minor	Minor
3	iii	C Minor	Minor
4	IV	D♭ Major	Major
5	V	E♭ Major	Major
6	vi	F Minor	Minor
7	vii°	G Diminished	Diminished

A♭ 9♯11 : Frequently Asked Questions

What is the A♭ 9♯11 chord on piano?

The A♭ 9♯11 chord contains the notes A♭ – C – E♭ – G♭ – B♭ – D. On piano, play these notes together to sound the chord.