The D Diminished Major 7th chord is a four-note chord made up of D, F, A♭, and C♯.
Construction
| Note | Interval | Degree |
|---|---|---|
| D | Root | 1 |
| F | Minor 3rd | ♭3 |
| A♭ | Diminished 5th | ♭5 |
| C♯ | Major 7th | 7 |
Key Signature
A Diminished Major 7th chord is built from symmetrical or ambiguous intervals, so it doesn’t belong to a single key and has no key signature of its own.