C Dim Chord Secrets: Piano & Guitar Theory Explained

The C diminished chord (often written as C dim) is a complex chord that adds color and dissonance to music. The notes that make up the C diminished chord are C, Eb, and Gb.

In this guide, we’ll cover how to play the C diminished chord on both piano and guitar.

Understanding the C Diminished Chord

The C diminished chord (often written as C dim) is a triad, or three-note chord, that has a root, a minor third, and a diminished fifth.

In the case of C dim, those notes are:

  • C (root)
  • Eb (minor third)
  • Gb (diminished fifth)

You may also see C diminished written as Cdim(b5)b5.

Playing the C Diminished Chord on Piano

The basic C diminished chord includes the notes C, Eb, and Gb. On the piano, place your thumb on C, your middle finger on Eb, and your pinky on Gb.

C Diminished Chord Inversions

  • First Inversion: Play Eb, then Gb, then C.
  • Second Inversion: Play Gb, then C, then Eb.

C Diminished 7th Chord

The C diminished 7th chord adds another note: C, Eb, Gb, and Bbb (B double flat).

C Diminished 7th Chord Inversions

  • First Inversion: Eb, Gb, Bbb, C
  • Second Inversion: Gb, Bbb, C, Eb
  • Third Inversion: Bbb, C, Eb, Gb

Playing a C diminished chord on guitar

Guitarists often use fretboard diagrams to visualize chord shapes, and the C diminished is no exception. Once you learn a fretboard pattern, you can move it around on the neck to play the chord with different roots, such as C diminished, D diminished, and so on.

There are several movable positions for the C diminished chord.

If you’re having trouble with bar chords, check out our “Bar Chord Tips” tutorial.

Summary

The C diminished chord is a versatile tool for adding a little dissonance and color to your music. Experiment with it in different contexts, and try out some inversions and variations.

Whether you play piano or guitar, understanding the C diminished chord unlocks some new and interesting creative possibilities.