Chord reference
Half-diminished seventh
1 – ♭3 – ♭5 – ♭7 · example: Cm7♭5 = C – E♭ – G♭ – B♭
A diminished triad with a minor seventh. Written m7♭5 or with the ø symbol.
Written as a formula it is 1 – ♭3 – ♭5 – ♭7: the degrees of the major scale it keeps, with any that are altered marked. On C that gives Cm7♭5 = C, E♭, G♭, B♭.
How it is built
- B♭minor
- G♭third
- E♭minor
- Croot
The intervals above the root
| Chord tone | Interval above the root | Semitones | Note in Cm7♭5 |
|---|---|---|---|
| 1 | Perfect unison | 0 | C |
| ♭3 | Minor third | 3 | E♭ |
| ♭5 | Diminished fifth | 6 | G♭ |
| ♭7 | Minor seventh | 10 | B♭ |
Inversions
The same notes can be stacked in any vertical order. The chord keeps its name; what changes is which note is in the bass. See chord inversions for why that matters.
| Position | Notes | Written as |
|---|---|---|
| Root position | C – E♭ – G♭ – B♭ | Cm7♭5 |
| First inversion | E♭ – G♭ – B♭ – C | Cm7♭5/E♭ |
| Second inversion | G♭ – B♭ – C – E♭ | Cm7♭5/G♭ |
| Third inversion | B♭ – C – E♭ – G♭ | Cm7♭5/B♭ |
This chord on every root
| Root | Symbol | Notes |
|---|---|---|
| C | Cm7♭5 | C – E♭ – G♭ – B♭ |
| D♭ | D♭m7♭5 | D♭ – F♭ – A𝄫 – C♭ |
| D | Dm7♭5 | D – F – A♭ – C |
| E♭ | E♭m7♭5 | E♭ – G♭ – B𝄫 – D♭ |
| E | Em7♭5 | E – G – B♭ – D |
| F | Fm7♭5 | F – A♭ – C♭ – E♭ |
| F♯ | F♯m7♭5 | F♯ – A – C – E |
| G | Gm7♭5 | G – B♭ – D♭ – F |
| A♭ | A♭m7♭5 | A♭ – C♭ – E𝄫 – G♭ |
| A | Am7♭5 | A – C – E♭ – G |
| B♭ | B♭m7♭5 | B♭ – D♭ – F♭ – A♭ |
| B | Bm7♭5 | B – D – F – A |