The B♭ Major 9♯11 chord is a six-note chord made up of B♭, C, D, E, F, and A.
Construction
B♭ Major 9♯11 = Root + Major 2nd + Major 3rd + Diminished 5th + Perfect 5th + Major 7th = B♭ · C · D · E · F · A
| Note | Interval | Degree |
|---|---|---|
| B♭ | Root | 1 |
| C | Major 2nd | 9 |
| D | Major 3rd | 3 |
| E | Diminished 5th | ♭5 |
| F | Perfect 5th | 5 |
| A | Major 7th | 7 |
Key Signature
A chord has no key signature of its own, but the B♭ Major 9♯11 is the tonic (I) chord of Bb 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 B♭ Major
These are the triads built on each degree of the B♭ major scale:
B♭ Major 9♯11 — Frequently Asked Questions
What is the B♭ Major 9♯11 chord on piano?
The B♭ Major 9♯11 chord contains the notes B♭ – C – D – E – F – A. On piano, play these notes together to sound the chord.