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C Diminished Chord

Cdim stacks two minor thirds: C to E flat, then E flat to G flat. Its lowered fifth creates a tritone above the root and gives the triad a strong need to move.

  • Notes: C-E flat-G flat
  • Symbol: Cdim
  • viidim in Db major
  • Lowered fifth
Switch chordCdim

How to play a C diminished chord

Notes: C - Eb - Gb · symbol Cdim

  • Root position

    C - Eb - Gb
    C4C5
    Right hand 1-3-5 · Left 5-3-1

  • 1st inversion

    Eb - Gb - C
    C4C5
    Right hand 1-2-5 · Left 5-3-1

  • 2nd inversion

    Gb - C - Eb
    C4C5
    Right hand 1-3-5 · Left 5-2-1

Where does C diminished belong?

In Db major, this diminished triad can act as a leading-tone chord that approaches the tonic.
Play the role cards to hear how its surrounding chords change the job it does; Diatonic Chords explains the basic numbered roles.

  • In Db majorLeading-tone chord
    vii°

    C is the leading tone of Db, so the chord leans hard toward it.

    DbIGbIVCdimvii°DbI
  • In Bb minorThe ii° in minor
    ii°

    The minor-key version of ii-V-i, heading to Bbm.

    Cdimii°FVBbmi
  • In C# minorMinor-key pull
    vii°

    From harmonic minor: the same chord pulls just as hard toward C#m. In this key the chord is spelled B#dim.

    C#miF#mivB#dimvii°C#mi

Progressions to try

  • DbGbCdimDb

    Cdim is a leading-tone triad that resolves by step into the final major tonic.

  • CdimFBbm

    In Bb minor, Cdim serves as ii diminished before the dominant and minor tonic.

  • C#mF#mB#dimC#m

    The leading-tone sound also works before a minor tonic; check the chord's spelling in this key. Here the same sounding chord is written B#dim rather than Cdim.

Which shape should you use?

On guitar, start with x3454x, played at the 3rd fret. Mute any strings marked x.

On ukulele, start with 5323, played at the 2nd fret. The 8686 grip moves the chord to another register.

On piano, play C-E flat-G flat. Move C up an octave to reach the first inversion, E flat-G flat-C; the notes remain the same while the lowest voice changes.

What are the inversions?

C is the root, E flat the minor third and G flat the diminished fifth, six semitones above the root.

  • Root position: C-E flat-G flat, with C lowest.
  • First inversion: E flat-G flat-C, written Cdim/Eb if E flat is lowest in the whole arrangement.
  • Second inversion: G flat-C-E flat, written Cdim/Gb if G flat is lowest in the whole arrangement.

A slash chord names the note in the bass, not merely the lowest note under one hand. Chord Inversions shows how to read that distinction.

How does Cdim differ from Cm?

Keep C and E flat, then raise the diminished fifth G flat to G. That makes Cm. This page is about the three-note diminished triad, not a diminished seventh chord. Try that one-note change on piano, then use the comparer to hear it in the full chord. See Cm for the other chord's full spelling and roles.

  • Cdim

    C - Eb - Gb
    C4

    C diminished

  • Cm

    C - Eb - G
    C4

    C minor

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