Explore chords · Bass
C diminished 7th chord on bass (Cdim7)
Also called or written Cdim7 or C°7
C diminished 7th contains C, E♭, G♭, and B♭♭. The 7th fret position requires precise finger placement to avoid muting adjacent strings.
How it is built
Formula 1, ♭3, ♭5, ♭♭7
- Root positionC–E♭–G♭–B♭♭Cdim78-9-7-8
- First inversionE♭–G♭–B♭♭–CCdim7/E♭11-12-10-11
- Second inversionG♭–B♭♭–C–E♭Cdim7/G♭2-3-1-2
- Third inversionB♭♭–C–E♭–G♭Cdim7/B♭♭5-6-4-5
How do you play a C diminished 7th chord on bass?
C diminished 7th is played at the 7th fret as 8 9 7 8: middle finger on the E string at fret 8, pinky finger on the A string at fret 9, index finger on the D string at fret 7 and ring finger on the G string at fret 8.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 8 | 2 | C (1) |
| 3 (A) | 9 | 4 | G♭ (♭5) |
| 2 (D) | 7 | 1 | B♭♭ (6) |
| 1 (G) | 8 | 3 | E♭ (♭3) |
AdvancedThe pinky must reach the 9th fret on the A string while the index holds the 7th fret on the D string, creating a wide stretch.
Cdim7/E♭ inversion
C diminished 7th is played at the 10th fret as 11 12 10 11: middle finger on the E string at fret 11, pinky finger on the A string at fret 12, index finger on the D string at fret 10 and ring finger on the G string at fret 11.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 11 | 2 | E♭ (♭3) |
| 3 (A) | 12 | 4 | B♭♭ (6) |
| 2 (D) | 10 | 1 | C (1) |
| 1 (G) | 11 | 3 | G♭ (♭5) |
Cdim7/G♭ inversion · fret 1
C diminished 7th is played at the 1st fret as 2 3 1 2: middle finger on the E string at fret 2, pinky finger on the A string at fret 3, index finger on the D string at fret 1 and ring finger on the G string at fret 2.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 2 | 2 | G♭ (♭5) |
| 3 (A) | 3 | 4 | C (1) |
| 2 (D) | 1 | 1 | E♭ (♭3) |
| 1 (G) | 2 | 3 | B♭♭ (6) |
Cdim7/G♭ inversion · fret 13
C diminished 7th is played at the 13th fret as 14 15 13 14: middle finger on the E string at fret 14, pinky finger on the A string at fret 15, index finger on the D string at fret 13 and ring finger on the G string at fret 14.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 14 | 2 | G♭ (♭5) |
| 3 (A) | 15 | 4 | C (1) |
| 2 (D) | 13 | 1 | E♭ (♭3) |
| 1 (G) | 14 | 3 | B♭♭ (6) |
Cdim7/B♭♭ inversion
C diminished 7th is played at the 4th fret as 5 6 4 5: middle finger on the E string at fret 5, pinky finger on the A string at fret 6, index finger on the D string at fret 4 and ring finger on the G string at fret 5.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 5 | 2 | B♭♭ (6) |
| 3 (A) | 6 | 4 | E♭ (♭3) |
| 2 (D) | 4 | 1 | G♭ (♭5) |
| 1 (G) | 5 | 3 | C (1) |
Why it sounds like that
C diminished 7th is built from the formula 1, ♭3, ♭5, ♭♭7. The diminished 5th between C and G♭ produces its unstable quality. Contrast it with C minor 7th flat 5th, which has a ♭7 instead of ♭♭7.
What goes wrong with C diminished 7th?
- Letting the pinky collapse and mute the 3rd string.
- Allowing the ring finger to touch the 1st string and dull its sound.
When to use it
Use the supplied linked chords to hear its tension without adding unsupported harmony. Use it in jazz, blues, and classical bass lines. It pairs with C minor 7th flat 5th in half-diminished contexts.
Changing to and from C diminished 7th
- Slide the shape down two frets to the 5th fret to reach B♭ diminished 7th.
- Slide the shape up one fret to the 8th fret to reach C♯ diminished 7th.
Which voicing to use
The 7th fret position keeps C as the lowest note on the E string, giving a solid foundation. The Cdim7/G♭ inversion at the 1st fret places G♭ in the bass for a darker, more ambiguous sound.
Other C chords
Common questions
How is C diminished 7th written?
C diminished 7th is written as C°7 or Cdim7.
Why does C diminished 7th use B♭♭ instead of A?
B♭♭ is the correct spelling for the diminished 7th above C. Using A would create a major 6th, which changes the chord's function.
Is C diminished 7th the same as E♭ diminished 7th?
C diminished 7th and E♭ diminished 7th share the same notes but have different roots. The spelling depends on which note is considered the root.