What notes are in a D diminished chord?

D diminished contains three notes: D (the root), F (the minor third), and A♭ (the diminished fifth).

What key uses D diminished as ii°?

C minor — D° → G7 → Cm is one of the most common cadences in Baroque and Classical music in C minor.

How is D diminished different from D minor?

Only the fifth changes. D minor (D–F–A) has a perfect fifth; D diminished (D–F–A♭) lowers that fifth, generating the tritone that drives toward resolution.

Where is D diminished used in jazz?

As the ii of a ii–V–i in C minor, often extended to Dm7♭5 (the half-diminished version). Standards like "Autumn Leaves" use this exact chord at every C-minor section.

D diminished chord — notes, intervals, and practice

D diminished — D, F, A♭ — is the ii° of C minor and a common chromatic passing chord in flat-side keys. The chord stacks two minor thirds with a tritone between root and fifth, producing the unstable, "needs-to-resolve" sound that defines diminished harmony.

Intervals

The D diminished chord stacks two thirds on the root. Each interval and its size in semitones:

D→Fminor 3rd3 semitones
F→Abminor 3rd3 semitones
D→Abdiminished 5th6 semitones

On the keyboard

Each note of the D diminished chord highlighted on a piano. Pitch class is what matters — any octave works.

On the guitar

One voicing of the D diminished chord on a six-string guitar fretboard.

Common mistakes

The fifth of D° is A♭, not A natural. Replacing A♭ with A makes a D minor chord — much less tense. The chord's flat in the middle of two naturals makes it visually distinctive in score; missing the A♭ is the most common reading error in C minor literature, where D° appears constantly as the supertonic chord.

In context

D° → G7 → C minor is the classic ii° → V → i cadence in C minor — one of the most common cadential patterns in Baroque and Classical music. Bach uses D° extensively in his C minor preludes and fugues. In E♭ major, D° serves as the vii° leading back to E♭ at section ends.

Drill it

The D diminished chord is one of 48 in the Chord Trainer. Open the full trainer to practice it alongside related chords with timing and best-time tracking.

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Frequently asked

What notes are in a D diminished chord?: D diminished contains three notes: D (the root), F (the minor third), and A♭ (the diminished fifth).
What key uses D diminished as ii°?: C minor — D° → G7 → Cm is one of the most common cadences in Baroque and Classical music in C minor.
How is D diminished different from D minor?: Only the fifth changes. D minor (D–F–A) has a perfect fifth; D diminished (D–F–A♭) lowers that fifth, generating the tritone that drives toward resolution.
Where is D diminished used in jazz?: As the ii of a ii–V–i in C minor, often extended to Dm7♭5 (the half-diminished version). Standards like "Autumn Leaves" use this exact chord at every C-minor section.