Chord · D Diminished 7th
Ddim7 Chord
Ddim7 is D, F, Ab and Cb — symmetrical; passes through every key. Used as a dominant substitute.
Ddim7 on every instrument
The same 4 notes, 6 sets of hands. Open a diagram for alternate shapes, audio and the mistakes to avoid.
What Ddim7 is made of
Ddim7 (D diminished seventh) is built from the notes D, F, Ab, Cb, with the interval pattern 1, b3, b5, bb7.
Stack 1, b3, b5 and bb7 on a root of D and you get D, F, Ab and Cb. That interval recipe is what makes the chord a diminished seventh chord — move the same shape to another root and the character travels with it, which is why Cdim7 sounds like a transposed Ddim7.
Diminished 7th: Symmetrical; passes through every key. Used as a dominant substitute.
Spelling: the notes above are written the way a score would write them, not simplified to the nearest piano key. That is why this chord is spelled with A♭ rather than its enharmonic equivalent.
Keys that contain Ddim7
No major or natural-minor key contains all 4 of these notes — this one gets borrowed.
Chords like this one sit outside the diatonic set — they arrive as secondary dominants, borrowed chords or passing harmony. Browse every key to see which progressions pull it in.
Other chords on D
Same root, different colour.
The same diminished seventh shape, moved
The identical interval recipe, built on other roots.
Questions people ask about Ddim7
- What notes are in the Ddim7 chord?
- Ddim7 is made of D, F, Ab and Cb — the 1, b3, b5 and bb7 degrees of a diminished seventh chord built on D.
- What keys use the Ddim7 chord?
- No major or natural-minor key contains all 4 notes of Ddim7. Chords like this arrive as borrowed harmony — secondary dominants, harmonic-minor colour, or chromatic passing chords — rather than as one of a key's native chords.
- How do you play Ddim7 on guitar and piano?
- This page shows Ddim7 on guitar, piano, ukulele, bass, mandolin and banjo — 9 voicings in total. Each diagram links to the full instrument page with alternate shapes, audio and common mistakes.
Learn the theory behind it
Why Ddim7 behaves the way it does — the guides that explain the chord instead of just spelling it.