G diminished 7th chord on bass (Gdim7)

Also called or written Gdim7 or G°7

G diminished 7th contains G, B♭, D♭, and F♭. The 2nd fret position requires a wide finger stretch across all four strings.

2frGD♭F♭B♭EADG
Positions on the neck1 of 4
Practice G diminished 7th chord

How it is built

GRootB♭Minor thirdD♭Diminished fifthF♭Minor seventh

Formula 1, ♭3, ♭5, ♭♭7

Inversions

How do you play a G diminished 7th chord on bass?

G diminished 7th is played at the 2nd fret as 3 4 2 3: middle finger on the E string at fret 3, pinky finger on the A string at fret 4, index finger on the D string at fret 2 and ring finger on the G string at fret 3.

Full note and interval breakdown
StringFretFingerNote
4 (E)32G (1)
3 (A)44D♭ (♭5)
2 (D)21F♭ (6)
1 (G)33B♭ (♭3)

AdvancedThe pinky must reach the 4th fret on the A string while the index holds the 2nd fret on the D string, creating a wide span.

Gdim7/B♭ inversion

G diminished 7th is played at the 5th fret as 6 7 5 6: middle finger on the E string at fret 6, pinky finger on the A string at fret 7, index finger on the D string at fret 5 and ring finger on the G string at fret 6.

Full note and interval breakdown
StringFretFingerNote
4 (E)62B♭ (♭3)
3 (A)74F♭ (6)
2 (D)51G (1)
1 (G)63D♭ (♭5)

Gdim7/D♭ inversion

G diminished 7th is played at the 8th fret as 9 10 8 9: middle finger on the E string at fret 9, pinky finger on the A string at fret 10, index finger on the D string at fret 8 and ring finger on the G string at fret 9.

Full note and interval breakdown
StringFretFingerNote
4 (E)92D♭ (♭5)
3 (A)104G (1)
2 (D)81B♭ (♭3)
1 (G)93F♭ (6)

Gdim7/F♭ inversion

G diminished 7th is played at the 11th fret as 12 13 11 12: middle finger on the E string at fret 12, pinky finger on the A string at fret 13, index finger on the D string at fret 11 and ring finger on the G string at fret 12.

Full note and interval breakdown
StringFretFingerNote
4 (E)122F♭ (6)
3 (A)134B♭ (♭3)
2 (D)111D♭ (♭5)
1 (G)123G (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♭ produces its tense sound. Compare it to G minor 7th flat 5th, which has a ♭7 instead of ♭♭7.

What goes wrong with G 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

G diminished 7th functions as a leading-tone chord in A♭ major or A♭ minor, resolving to A♭. Use it in jazz turnarounds and classical bass lines. It also connects to G minor 7th flat 5th in ii–V progressions.

Changing to and from G diminished 7th

  • Slide the shape down one fret to the 1st fret to reach F♯ diminished 7th.
  • Slide the shape up one fret to the 3rd fret to reach A♭ diminished 7th.

Which voicing to use

The 2nd fret position gives G as the lowest note on the E string, providing a strong root. The Gdim7/B♭ inversion at the 5th fret places B♭ in the bass for a darker, more ambiguous sound.

Other G chords

Common questions

How is G diminished 7th written?

G diminished 7th is written as G°7 or Gdim7.

Why does G diminished 7th use F♭ instead of E?

F♭ is the correct spelling for the diminished 7th above G. Using E would create a major 6th, which changes the chord's function.

Is G diminished 7th the same as B♭ diminished 7th?

G diminished 7th and B♭ diminished 7th share the same notes but have different roots. The spelling depends on which note is considered the root.