Ddim7

D Diminished 7th — perfectly symmetrical stacked minor thirds — the ultimate passing chord, able to resolve almost anywhere.

The keys
C4C5C6
D – F – A♭ – C♭
What's inside Ddim7
NoteInterval from rootDegree
DRoot1
FMinor 3rdb3
A♭Diminished 5thb5
C♭Diminished 7thbb7
Inversions
PositionKeys (low → high)
Root positionD4 – F4 – A♭4 – B4
1st inversionF4 – A♭4 – B4 – D5
2nd inversionA♭4 – B4 – D5 – F5
3rd inversionB4 – D5 – F5 – A♭5
A working voicing

Split the chord between two hands the way working players do — a solid shell low down, the colour tones up top:

HandKeys
Left (shell)D2 – B2
Right (colour)F4 – A♭4
Where Ddim7 lives

As the ii chord

Ddim7 → G7 → Cmaj7

Minor-family sevenths live on the ii — this is the move they were born for.

Stepwise colour

D → Ddim7 → Em7

Used as a passing colour between neighbouring chords.

Put Ddim7 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 →