C diminished chord on bass (Cdim)

Also called or written Cdim or

C diminished contains C, E♭, and G♭. The 8th-fret shape is a one-finger-per-string stretch that sits high on the neck.

8frCG♭CE♭EADG
Positions on the neck1 of 5
Practice C diminished chord

How it is built

CRootE♭Minor thirdG♭Diminished fifth

Formula 1, ♭3, ♭5

Inversions

How do you play a C diminished chord on bass?

C diminished is played at the 8th fret as 8 9 10 8: index finger on the E string at fret 8, ring finger on the A string at fret 9, pinky finger on the D string at fret 10 and middle finger on the G string at fret 8.

Full note and interval breakdown
StringFretFingerNote
4 (E)81C (1)
3 (A)93G♭ (♭5)
2 (D)104C (1)
1 (G)82E♭ (♭3)

IntermediateThe pinky must reach the 10th fret on the 2nd string while the middle finger holds the 8th fret on the 1st string.

Cdim/E♭ inversion

C diminished is played at the 9th fret as 11 9 10 11: ring finger on the E string at fret 11, index finger on the A string at fret 9, middle finger on the D string at fret 10 and pinky finger on the G string at fret 11.

Full note and interval breakdown
StringFretFingerNote
4 (E)113E♭ (♭3)
3 (A)91G♭ (♭5)
2 (D)102C (1)
1 (G)114G♭ (♭5)

Cdim/G♭ inversion · fret 1

C diminished is played at the 1st fret as 2 3 1 ×: middle finger on the E string at fret 2, ring finger on the A string at fret 3 and index finger on the D string at fret 1. The G string stays muted.

Full note and interval breakdown
StringFretFingerNote
4 (E)22G♭ (♭5)
3 (A)33C (1)
2 (D)11E♭ (♭3)
1 (G)muted

Cdim/G♭ inversion · fret 8

C diminished is played at the 8th fret as × 9 10 8: middle finger on the A string at fret 9, ring finger on the D string at fret 10 and index finger on the G string at fret 8. The E string stays muted.

Full note and interval breakdown
StringFretFingerNote
4 (E)muted
3 (A)92G♭ (♭5)
2 (D)103C (1)
1 (G)81E♭ (♭3)

Cdim/G♭ inversion · fret 13

C diminished is played at the 13th fret as 14 15 13 ×: middle finger on the E string at fret 14, ring finger on the A string at fret 15 and index finger on the D string at fret 13. The G string stays muted.

Full note and interval breakdown
StringFretFingerNote
4 (E)142G♭ (♭5)
3 (A)153C (1)
2 (D)131E♭ (♭3)
1 (G)muted

Why it sounds like that

C diminished is built from the formula 1, ♭3, ♭5. The ♭5 interval gives the chord its tense, unstable quality. Compare C minor, which raises the fifth to G.

What goes wrong with C diminished?

  • Letting the pinky collapse onto the 1st string mutes the G.
  • Pressing the index finger too flat on the 4th string buzzes against the fret.
  • Arching the ring finger too high pulls the 3rd string sharp.

When to use it

C diminished works as a passing chord between C minor and E♭ major, or over a B♭ natural minor line. The ♭5 interval creates a tritone that pulls toward the next chord, suiting jazz walk-ups and metal riffs.

Changing to and from C diminished

  • Sliding the shape down two frets to the 6th fret gives B♭ diminished.
  • Move to C minor by raising the 2nd string one fret to the 11th fret.

Which voicing to use

The 8th-fret shape puts C in the bass for a root-position sound. The Cdim/E♭ inversion at the 11th fret places E♭ in the bass, which softens the chord's bite.

Other C chords

Common questions

How do I write C diminished?

Write C° or Cdim. The root is C, and the chord is spelled C–E♭–G♭.

Why does C diminished sound unstable?

The ♭5 interval creates a tritone with the root, which wants to resolve. This tension is what gives diminished chords their forward drive.

Can I use C diminished in place of C minor?

Only when you want that darker, more dissonant color. C diminished lowers the fifth, so it clashes with melodies that expect the perfect fifth G.