B♭7
Bb Dominant 7th — the engine of harmonic motion — the tritone between its third and seventh drives resolution down a fifth.
The keys
B♭ – D – F – A♭
What's inside B♭7
| Note | Interval from root | Degree |
|---|---|---|
| B♭ | Root | 1 |
| D | Major 3rd | 3 |
| F | Perfect 5th | 5 |
| A♭ | Minor 7th | b7 |
Inversions
| Position | Keys (low → high) |
|---|---|
| Root position | B♭4 – D5 – F5 – A♭5 |
| 1st inversion | D5 – F5 – A♭5 – B♭5 |
| 2nd inversion | F5 – A♭5 – B♭5 – D6 |
| 3rd inversion | A♭5 – B♭5 – D6 – F6 |
A working voicing
Split the chord between two hands the way working players do — a solid shell low down, the colour tones up top:
| Hand | Keys |
|---|---|
| Left (shell) | B♭2 – A♭3 |
| Right (colour) | D5 – F5 |
Where B♭7 lives
Resolving down a fifth
B♭7 → E♭
The defining dominant move: the tritone inside this chord releases onto the chord a fifth below.
In a ii–V–I
Fm7 → B♭7 → E♭maj7
This chord as the V — the engine of the most-used cadence in music.
Put B♭7 under your fingers
Hear every voicing, see the keys light up, and drill it in the interactive Chord & Voicing Lab.
Open the Chord & Voicing Lab →