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C diminished 7th chord on ukulele (Cdim7)
Also called or written Cdim7 or C°7
C diminished 7th is built from C, E♭, G♭, B♭♭. The 5th fret shape is a compact four-finger cluster that moves cleanly up and down the neck.
How it is built
Formula 1, ♭3, ♭5, ♭♭7
- Root positionC–E♭–G♭–B♭♭Cdim711-12-11-12
- First inversionE♭–G♭–B♭♭–CCdim7/E♭2-3-2-3
- Second inversionG♭–B♭♭–C–E♭Cdim7/G♭5-6-5-6
- Third inversionB♭♭–C–E♭–G♭Cdim7/B♭♭8-9-8-9
How do you play a C diminished 7th chord on ukulele?
C diminished 7th is played at the 5th fret as 5 6 5 6: index finger on the G string at fret 5, ring finger on the C string at fret 6, middle finger on the E string at fret 5 and pinky finger on the A string at fret 6.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (G) | 5 | 1 | C (1) |
| 3 (C) | 6 | 3 | G♭ (♭5) |
| 2 (E) | 5 | 2 | B♭♭ (6) |
| 1 (A) | 6 | 4 | E♭ (♭3) |
AdvancedThe pinky must reach fret 6 on the A string while the ring finger holds fret 6 on the C string, requiring a wide stretch.
Cdim7/B♭♭ inversion
C diminished 7th is played at the 8th fret as 8 9 8 9: index finger on the G string at fret 8, ring finger on the C string at fret 9, middle finger on the E string at fret 8 and pinky finger on the A string at fret 9.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (G) | 8 | 1 | E♭ (♭3) |
| 3 (C) | 9 | 3 | B♭♭ (6) |
| 2 (E) | 8 | 2 | C (1) |
| 1 (A) | 9 | 4 | G♭ (♭5) |
11th fret
C diminished 7th is played at the 11th fret as 11 12 11 12: index finger on the G string at fret 11, ring finger on the C string at fret 12, middle finger on the E string at fret 11 and pinky finger on the A string at fret 12.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (G) | 11 | 1 | G♭ (♭5) |
| 3 (C) | 12 | 3 | C (1) |
| 2 (E) | 11 | 2 | E♭ (♭3) |
| 1 (A) | 12 | 4 | B♭♭ (6) |
Cdim7/E♭ inversion
C diminished 7th is played at the 2nd fret as 2 3 2 3: index finger on the G string at fret 2, ring finger on the C string at fret 3, middle finger on the E string at fret 2 and pinky finger on the A string at fret 3.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (G) | 2 | 1 | B♭♭ (6) |
| 3 (C) | 3 | 3 | E♭ (♭3) |
| 2 (E) | 2 | 2 | G♭ (♭5) |
| 1 (A) | 3 | 4 | C (1) |
Why it sounds like that
C diminished 7th stacks minor thirds: 1, ♭3, ♭5, ♭♭7. The ♭♭7, B♭♭, sounds like A but is spelled as a diminished seventh to preserve the chord's structure. Compare it with C minor 7th flat 5th, which has a minor seventh instead.
What goes wrong with C diminished 7th?
- Letting the index finger mute the C string by lying flat.
- Pressing the pinky on the A string fret 6 without enough arch, deadening the E string.
- Strumming before all four fingers are firmly placed.
When to use it
C diminished 7th works as a passing chord between C minor 7th flat 5th and D minor. Its tense, symmetrical sound suits jazz turnarounds and dramatic pauses in ballads.
Changing to and from C diminished 7th
- Sliding the shape down one fret to the 4th fret gives B diminished 7th.
- Sliding the shape up one fret to the 6th fret gives C♯ diminished 7th.
Which voicing to use
The 5th fret voicing puts C in the bass, giving the most direct root-position sound. The Cdim7/E♭ inversion at the 8th fret places E♭ in the bass, which softens the chord's attack and works well when moving to a D chord.
Other C chords
Common questions
How is C diminished 7th written?
C diminished 7th is written C°7 or Cdim7. The root is C. The chord is sometimes called C diminished seventh.
Why does C diminished 7th use B♭♭ instead of A?
The diminished seventh interval from C is B♭♭, not A. Spelling it B♭♭ keeps the chord's formula as 1, ♭3, ♭5, ♭♭7. Using A would make the interval a major sixth.
How does C diminished 7th differ from C minor 7th flat 5th?
C minor 7th flat 5th has a minor seventh, B♭, while C diminished 7th has a diminished seventh, B♭♭. That one-semitone difference makes the diminished chord sound more tense and symmetrical.
Can I play C diminished 7th with a barre?
No, the 5th fret voicing uses four separate fingers. A barre would fret the G and E strings at fret 5, but you still need fingers for the C and A strings at fret 6.