C diminished chord (Cdim)
The C diminished chord (Cdim) is a diminished triad: C, E♭ and G♭, two minor thirds stacked on top of each other (root, minor third and diminished fifth).
It is the vii° in D♭ major and the ii° in B♭ minor; it sits inside A♭ dominant seventh and tends to resolve to D♭ major, a half step up.
Below: voicings, notes on the fretboard, ukulele, piano, inversions and progressions.
How to play C diminished on guitar
There are 2 guitar voicings.
Frets from the 6th string to the 1st: x = not played, 0 = open string.
- Voicing 1: x-3-4-5-4-x, with C in the bass (fingers x-1-2-4-3-x).
- Voicing 2: 8-9-10-8-x-x, barre at fret 8, with C in the bass (fingers 1-2-4-1-x-x).
Notes of the C diminished chord on the fretboard
C diminished has 3 notes: C, E♭ and G♭. This is where they fall on each string, from the nut to the 12th fret (fret number in parentheses):
- String 6 (E): G♭ (2) · C (8) · E♭ (11)
- String 5 (A): C (3) · E♭ (6) · G♭ (9)
- String 4 (D): E♭ (1) · G♭ (4) · C (10)
- String 3 (G): C (5) · E♭ (8) · G♭ (11)
- String 2 (B): C (1) · E♭ (4) · G♭ (7)
- String 1 (E): G♭ (2) · C (8) · E♭ (11)
Formula and intervals of C diminished
Its formula is 1-♭3-♭5; in semitones from the root, 0-3-6.
- C: Root, the note that gives the chord its name
- E♭: Minor third (m3), 3 semitones above C
- G♭: Diminished fifth (d5), 6 semitones above C
C diminished on ukulele
- Ukulele (G C E A): 5-3-2-3; it sounds C, E♭, G♭ and C.
C diminished on piano
- Keys: C4, E♭4 and G♭4.
Inversions of C diminished
Each inversion puts a different note in the bass.
- Root position: C, E♭ and G♭, with C in the bass.
- First inversion (Cdim/E♭): E♭, G♭ and C, with E♭ in the bass.
- Second inversion (Cdim/G♭): G♭, C and E♭, with G♭ in the bass.
Keys that use C diminished
C diminished appears in 3 major and minor keys.
| Key | Degree | Function |
|---|---|---|
| D♭ major (5 flats) | vii° | Leading tone |
| B♭ minor (5 flats) | ii° | Supertonic |
| C♯ minor (harmonic minor, 4 sharps) | vii° (written B♯dim) | Leading tone |
Progressions with C diminished
- Passing diminished chord in B major (I–♯i°–ii–V): B – B♯dim – C♯m – F♯
Frequently asked questions
What notes are in the C diminished chord?
C, E♭ and G♭: root, minor third and diminished fifth. Its formula is 1-♭3-♭5.
Which keys use C diminished?
Mainly as the vii° in D♭ major and the ii° in B♭ minor. In total it appears in 3 major and minor keys.
Is C diminished the same as a diminished seventh chord?
No: C diminished is a triad with three notes (C, E♭ and G♭). A diminished seventh chord adds a fourth note, another minor third on top.
Why does C diminished sound like A♭ dominant seventh?
Because its three notes, C, E♭ and G♭, are the third, fifth and seventh of A♭ dominant seventh: it is that dominant seventh without its root. So it does the same job and resolves to D♭ major.