The D Half Diminished chord is a four-note chord made up of D, F, A♭, and C. It is built from a root, minor third, diminished fifth, and minor seventh.
Construction
| Note | Interval | Degree |
|---|---|---|
| D | Root | 1 |
| F | Minor 3rd | ♭3 |
| A♭ | Diminished 5th | ♭5 |
| C | Minor 7th | ♭7 |
D Half Diminished Inversions



| Position | Notes |
|---|---|
| Root Position | D – F – A♭ – C |
| 1st Inversion | F – A♭ – C – D |
| 2nd Inversion | A♭ – C – D – F |
| 3rd Inversion | C – D – F – A♭ |
Key Signature
A Half Diminished 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.
How D Half Diminished functions in a key
The same chord takes on a different harmonic role depending on the key it appears in. Here is where D Half Diminished sits diatonically across the common keys:
- In E♭ major, D Half Diminished is the vii° chord — the dominant.
- In C minor, D Half Diminished is the ii° chord — a predominant.
Same Notes, Other Names
The notes D – F – A♭ – C aren’t exclusive to this chord. Depending on which note is the bass and how the chord functions, the same pitches also spell: