A♯maj9♯11: A♯/B♭ Major 9th Sharp 11th Piano Chord

Construction

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

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

Key Signature

A chord has no key signature of its own, but the A♯ Major 9♯11 is the tonic (I) chord of A♯ Major, whose key signature has 2 flats (B♭, E♭).

B♭E♭

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♯ Major 9♯11 : Frequently Asked Questions

What is the A♯ Major 9♯11 chord on piano?

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

What is the A# piano chord?

The A# piano chord (written A♯ Major 9♯11) uses the same keys: A♯ – C♯♯ – E♯ – G♯♯ – B♯ – D♯♯. The # and ♯ symbols name the same black key.