Chord reference
Diminished seventh
1 – ♭3 – ♭5 – ♭♭7 · example: Cdim7 = C – E♭ – G♭ – B𝄫
Three stacked minor thirds. It divides the octave evenly, so every inversion sounds like a root position.
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 Cdim7 = 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 Cdim7 |
|---|---|---|---|
| 1 | Perfect unison | 0 | C |
| ♭3 | Minor third | 3 | E♭ |
| ♭5 | Diminished fifth | 6 | G♭ |
| ♭♭7 | Diminished seventh | 9 | 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𝄫 | Cdim7 |
| First inversion | E♭ – G♭ – B𝄫 – C | Cdim7/E♭ |
| Second inversion | G♭ – B𝄫 – C – E♭ | Cdim7/G♭ |
| Third inversion | B𝄫 – C – E♭ – G♭ | Cdim7/B𝄫 |
This chord on every root
| Root | Symbol | Notes |
|---|---|---|
| C | Cdim7 | C – E♭ – G♭ – B𝄫 |
| D♭ | D♭dim7 | D♭ – F♭ – A𝄫 – C𝄫 |
| D | Ddim7 | D – F – A♭ – C♭ |
| E♭ | E♭dim7 | E♭ – G♭ – B𝄫 – D𝄫 |
| E | Edim7 | E – G – B♭ – D♭ |
| F | Fdim7 | F – A♭ – C♭ – E𝄫 |
| F♯ | F♯dim7 | F♯ – A – C – E♭ |
| G | Gdim7 | G – B♭ – D♭ – F♭ |
| A♭ | A♭dim7 | A♭ – C♭ – E𝄫 – G𝄫 |
| A | Adim7 | A – C – E♭ – G♭ |
| B♭ | B♭dim7 | B♭ – D♭ – F♭ – A𝄫 |
| B | Bdim7 | B – D – F – A♭ |