Chord · 7ths

Cdim7 — C Diminished 7th

Cdim7 is the C diminished 7th chord. It is built on the root C with minor 3rd (E♭), diminished 5th (G♭) and diminished 7th (B𝄫) above it — the formula 1 ♭3 ♭5 𝄫7, sounding the notes C E♭ G♭ B𝄫. On the piano it sits at C (octave 4) and above in the library's voicing; the same 4 notes in any octave are still Cdim7.

Root
C
Quality
Diminished 7th
Formula
1 ♭3 ♭5 𝄫7
Notes
C E♭ G♭ B𝄫

On the keyboard

Cdim7 on the piano keyboard: C E♭ G♭ B𝄫1235CE♭G♭B𝄫

Right-hand fingering for this voicing: 1–2–3–5 (1 is the thumb).

The notes of Cdim7

DegreeNoteInterval from the rootPitch
1CrootC4
♭3E♭minor 3rdE♭4
♭5G♭diminished 5thG♭4
𝄫7B𝄫diminished 7thB♭♭4

Other 7ths on C

Diminished 7th chords on every root

Part of the chord reference. See also the scales and the keys.