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G diminished 7th chord on ukulele (Gdim7)
Also called or written Gdim7 or G°7
G diminished 7th contains G, B♭, D♭, and F♭. This open shape is surprisingly easy to fret, but its unstable sound demands careful placement.
How it is built
Formula 1, ♭3, ♭5, ♭♭7
How do you play a G diminished 7th chord on ukulele?
G diminished 7th is played in open position as 0 1 0 1: index finger on the C string at fret 1 and middle finger on the A string at fret 1. The G and E strings ring open.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (G) | open | — | G (1) |
| 3 (C) | 1 | 1 | D♭ (♭5) |
| 2 (E) | open | — | F♭ (6) |
| 1 (A) | 1 | 2 | B♭ (♭3) |
AdvancedThe open shape requires precise placement of two fingers on adjacent strings at the same fret without touching the open strings.
Gdim7/F♭ inversion
G diminished 7th is played at the 3rd fret as 3 4 3 4: index finger on the G string at fret 3, ring finger on the C string at fret 4, middle finger on the E string at fret 3 and pinky finger on the A string at fret 4.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (G) | 3 | 1 | B♭ (♭3) |
| 3 (C) | 4 | 3 | F♭ (6) |
| 2 (E) | 3 | 2 | G (1) |
| 1 (A) | 4 | 4 | D♭ (♭5) |
6th fret
G diminished 7th is played at the 6th fret as 6 7 6 7: index finger on the G string at fret 6, ring finger on the C string at fret 7, middle finger on the E string at fret 6 and pinky finger on the A string at fret 7.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (G) | 6 | 1 | D♭ (♭5) |
| 3 (C) | 7 | 3 | G (1) |
| 2 (E) | 6 | 2 | B♭ (♭3) |
| 1 (A) | 7 | 4 | F♭ (6) |
Gdim7/B♭ inversion
G diminished 7th is played at the 9th fret as 9 10 9 10: index finger on the G string at fret 9, ring finger on the C string at fret 10, middle finger on the E string at fret 9 and pinky finger on the A string at fret 10.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (G) | 9 | 1 | F♭ (6) |
| 3 (C) | 10 | 3 | B♭ (♭3) |
| 2 (E) | 9 | 2 | D♭ (♭5) |
| 1 (A) | 10 | 4 | G (1) |
Why it sounds like that
G diminished 7th is built from the formula 1, ♭3, ♭5, ♭♭7. The diminished 5th between G and D♭ gives the chord its tense, unstable quality. Compare it to G minor 7th flat 5th, which has a minor 7th instead of a diminished 7th.
What goes wrong with G diminished 7th?
- Let the index finger lean against the open E string, deadening it.
- Let the middle finger touch the open G string, muting the root.
- Press too hard on the fretted notes, causing them to sound sharp.
When to use it
G diminished 7th works as a passing chord between G minor 7th flat 5th and A minor. It suits jazz, classical, and dramatic transitions where tension needs to resolve quickly.
Changing to and from G diminished 7th
- From G diminished 7th to A minor: lift both fingers and place the middle finger on the 2nd fret of the G string while the index finger stays on the 1st fret of the C string.
- From G diminished 7th to G minor 7th flat 5th: keep the index finger on the 1st fret of the C string and add the ring finger to the 1st fret of the E string.
Which voicing to use
The open position is the easiest to grab, but the B♭ inversion at the 3rd fret gives a darker, more compact sound. For a brighter, higher register, use the D♭ inversion at the 6th fret.
Other G chords
Common questions
How is G diminished 7th written?
G diminished 7th is written as G°7 or Gdim7.
What is the difference between G diminished 7th and G minor 7th flat 5th?
G diminished 7th has a diminished 7th (F♭), while G minor 7th flat 5th has a minor 7th (F). The diminished 7th creates a more tense and symmetrical sound.
Why does G diminished 7th sound unstable?
G diminished 7th contains two tritones: G–D♭ and B♭–F♭. These intervals create a strong pull toward resolution, making the chord sound restless.
Can G diminished 7th be used in place of a dominant chord?
Yes, G diminished 7th can substitute for A7 in a progression. The chord shares three notes with A7♭9, giving it a dominant function.