The A♯ Add 9 chord is a four-note chord made up of A♯, C♯♯, E♯, and B♯. It is built from a root, major third, perfect fifth, and major ninth.
Construction
A♯ Add 9 = Root + Major 3rd + Perfect 5th + Major 2nd = A♯ · C♯♯ · E♯ · B♯
| Note | Interval | Degree |
|---|---|---|
| A♯ | Root | 1 |
| C♯♯ | Major 3rd | 3 |
| E♯ | Perfect 5th | 5 |
| B♯ | Major 2nd | 2 |
A♯ Add 9 Inversions
| Position | Notes |
|---|---|
| Root Position | A♯ – C♯♯ – E♯ – B♯ |
| 1st Inversion | C♯♯ – E♯ – B♯ – A♯ |
| 2nd Inversion | E♯ – B♯ – A♯ – C♯♯ |
| 3rd Inversion | B♯ – A♯ – C♯♯ – E♯ |
Key Signature
A chord has no key signature of its own, but the A♯ Add 9 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 the A♯ major scale:
Same Notes, Other Names
The notes A♯ – C♯♯ – E♯ – B♯ aren’t exclusive to this chord. Depending on which note is the bass and how the chord functions, the same pitches also spell:
A♯ Add 9 — Frequently Asked Questions
What is the A♯ Add 9 chord on piano?
The A♯ Add 9 chord contains the notes A♯ – C♯♯ – E♯ – B♯. On piano, play these notes together to sound the chord.
What notes are in the A# Add 9 chord?
A# Add 9 is built from the A# root. Check the interactive keyboard above for exact notes and fingering.
How is the A# Add 9 chord used in music?
A# Add 9 appears in jazz, pop, and classical contexts. Its sound depends on the chord quality (Add 9).
What is the fingering for A# Add 9?
See the fingering chart above. Right hand typically uses thumb on root. Left hand uses pinky on root.
What are the inversions of A# Add 9?
Use the inversion buttons above to see each inversion with notes, fingering, and staff notation.