B♭m7♭5
Bb Half-Diminished — the half-diminished — a minor seventh with a flattened fifth, the classic ii chord in minor keys.
The keys
B♭ – D♭ – F♭ – A♭
What's inside B♭m7♭5
| Note | Interval from root | Degree |
|---|---|---|
| B♭ | Root | 1 |
| D♭ | Minor 3rd | b3 |
| F♭ | Diminished 5th | b5 |
| A♭ | Minor 7th | b7 |
Inversions
| Position | Keys (low → high) |
|---|---|
| Root position | B♭4 – D♭5 – E5 – A♭5 |
| 1st inversion | D♭5 – E5 – A♭5 – B♭5 |
| 2nd inversion | E5 – A♭5 – B♭5 – D♭6 |
| 3rd inversion | A♭5 – B♭5 – D♭6 – E6 |
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) | D♭5 – E5 |
Where B♭m7♭5 lives
As the ii chord
B♭m7♭5 → E♭7 → A♭maj7
Minor-family sevenths live on the ii — this is the move they were born for.
Stepwise colour
B♭ → B♭m7♭5 → Cm7
Used as a passing colour between neighbouring chords.
Put B♭m7♭5 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 →