The B♭ 7♯5 chord is a four-note chord made up of B♭, D, F♯, and A♭. It is built from a root, major third, augmented fifth, and minor seventh.
Construction
B♭ 7♯5 = Root + Major 3rd + Minor 6th + Minor 7th = B♭ · D · F♯ · A♭
| Note | Interval | Degree |
|---|---|---|
| B♭ | Root | 1 |
| D | Major 3rd | 3 |
| F♯ | Minor 6th | ♯5 |
| A♭ | Minor 7th | ♭7 |
B♭ 7♯5 Inversions
| Position | Notes |
|---|---|
| Root Position | B♭ – D – F♯ – A♭ |
| 1st Inversion | D – F♯ – A♭ – B♭ |
| 2nd Inversion | F♯ – A♭ – B♭ – D |
| 3rd Inversion | A♭ – B♭ – D – F♯ |
Key Signature
A chord has no key signature of its own, but the B♭ 7♯5 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:
Same Notes, Other Names
The notes B♭ – D – F♯ – A♭ aren’t exclusive to this chord. Depending on which note is the bass and how the chord functions, the same pitches also spell:
B♭ 7♯5 — Frequently Asked Questions
What is the B♭ 7♯5 chord on piano?
The B♭ 7♯5 chord contains the notes B♭ – D – F♯ – A♭. On piano, play these notes together to sound the chord.
What notes are in the Bb 7♯5 chord?
The Bb 7♯5 chord (Bb7♯5) contains 4 notes: Bb, D, F#, Ab. Formula: R-M3-A5-m7.
How is Bb7♯5 used in music?
Bb7♯5 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 Bb7♯5?
Bb7♯5 uses scale degrees 1-3-#5-b7, giving it its distinctive sound.