The B♭ Dominant 9th chord is a five-note chord made up of B♭, D, F, A♭, and C. It is built from a root, major third, perfect fifth, minor seventh, and major ninth.
Construction
B♭ Dominant 9th = Root + Major 3rd + Perfect 5th + Minor 7th + Major 2nd = B♭ · D · F · A♭ · C
| Note | Interval | Degree |
|---|---|---|
| B♭ | Root | 1 |
| D | Major 3rd | 3 |
| F | Perfect 5th | 5 |
| A♭ | Minor 7th | ♭7 |
| C | Major 2nd | 9 |
Key Signature
A dominant chord points home to the key a fifth below its root: the B♭ Dominant 9th is the V (dominant) of Eb Major, so the relevant key signature is that key’s — 3 flats (B♭, E♭, A♭). Spelled as a scale, these notes are Bb Mixolydian.
B♭E♭A♭
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 E♭ Major
These are the triads built on each degree of the E♭ major scale:
B♭ Dominant 9th — Frequently Asked Questions
What is the B♭ Dominant 9th chord on piano?
The B♭ Dominant 9th chord contains the notes B♭ – D – F – A♭ – C. On piano, play these notes together to sound the chord.
What notes are in the Bb Dominant 9th chord?
The Bb Dominant 9th chord (Bb9) contains 5 notes: Bb, D, F, Ab, C. Formula: R-M3-P5-m7-M9.
How is Bb9 used in music?
Bb9 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 Bb9?
Bb9 uses scale degrees 1-3-5-b7-9, giving it its distinctive sound.