G diminished 7th chord on guitar (Gdim7)

Also called or written Gdim7 or G°7

G diminished 7th is built from G, B♭, D♭, and F♭. The open voicing uses all six strings with no muting.

GB♭F♭GD♭F♭EADGBE
Positions on the neck1 of 5
Practice G diminished 7th chord

How it is built

GRootB♭Minor thirdD♭Diminished fifthF♭Minor seventh

Formula 1, ♭3, ♭5, ♭♭7

Inversions
  • Root positionG–B♭–D♭–F♭Gdim73-1-2-0-2-0
  • First inversionB♭–D♭–F♭–GGdim7/B♭×-1-2-0-2-0
  • Second inversionD♭–F♭–G–B♭Gdim7/D♭×-4-2-3-2-3
  • Third inversionF♭–G–B♭–D♭Gdim7/F♭0-1-2-0-2-0

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

G diminished 7th is played in open position as 3 1 2 0 2 0: pinky finger on the low E string at fret 3, index finger on the A string at fret 1, middle finger on the D string at fret 2 and ring finger on the B string at fret 2. The G and high e strings ring open.

Full note and interval breakdown
StringFretFingerNote
6 (E)34G (1)
5 (A)11B♭ (♭3)
4 (D)22F♭ (6)
3 (G)openG (1)
2 (B)23D♭ (♭5)
1 (e)openF♭ (6)

AdvancedThe open voicing requires fretting four strings while keeping two open strings ringing clearly.

2nd fret

G diminished 7th is played at the 2nd fret as 3 4 2 3 2 ×: barre your index finger across fret 2, middle finger on the low E string at fret 3, pinky finger on the A string at fret 4 and ring finger on the G string at fret 3. The high e string stays muted.

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

3rd fret

G diminished 7th is played at the 3rd fret as 3 4 5 3 5 3: barre your index finger across fret 3, middle finger on the A string at fret 4, ring finger on the D string at fret 5 and pinky finger on the B string at fret 5.

Full note and interval breakdown
StringFretFingerNote
6 (E)31 (barre)G (1)
5 (A)42D♭ (♭5)
4 (D)53G (1)
3 (G)31 (barre)B♭ (♭3)
2 (B)54F♭ (6)
1 (e)31 (barre)G (1)

5th fret

G diminished 7th is played at the 5th fret as × × 5 6 5 6: index finger on the D string at fret 5, ring finger on the G string at fret 6, middle finger on the B string at fret 5 and pinky finger on the high e string at fret 6. The low E and A strings stay muted.

Full note and interval breakdown
StringFretFingerNote
6 (E)muted
5 (A)muted
4 (D)51G (1)
3 (G)63D♭ (♭5)
2 (B)52F♭ (6)
1 (e)64B♭ (♭3)

8th fret

G diminished 7th is played at the 8th fret as × 10 8 9 8 9: barre your index finger across fret 8, pinky finger on the A string at fret 10, middle finger on the G string at fret 9 and ring finger on the high e string at fret 9. The low E string stays muted.

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

Why it sounds like that

G diminished 7th stacks three minor 3rds on G: 1, ♭3, ♭5, ♭♭7. The diminished 5th between G and D♭ gives the chord its tense quality. Compare it with G minor 7th flat 5th, which has a ♭7 instead of a ♭♭7.

What goes wrong with G diminished 7th?

  • Flattening the pinky onto the A string, muting the note.
  • Pressing the index finger too hard on the A string, causing the note to go sharp.
  • Letting the ring finger touch the high E string, muting the open note.

When to use it

G diminished 7th often functions as a leading-tone chord in A♭ major or A♭ minor, resolving to A♭ major or A♭ minor. Its tense sound suits classical cadences and jazz turnarounds. Try it before A♭ major or A♭ minor.

Changing to and from G diminished 7th

  • Move to <a href="/guitar/f-sharp-dim-7-chord">F♯ diminished 7th</a> by sliding the shape down one fret to the 2nd fret.
  • Shift to <a href="/guitar/a-flat-dim-7-chord">A♭ diminished 7th</a> by moving the fretted notes up one fret while keeping the open strings.

Which voicing to use

The open voicing keeps G in the bass and is the easiest to play. The 8th fret barre version offers a higher register with the same bass note but more sustain.

Other G chords

Common questions

How is G diminished 7th written?

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

What is the difference between G diminished 7th and G minor 7th flat 5th?

G diminished 7th has a ♭♭7 (F♭), while G minor 7th flat 5th has a ♭7 (F). The diminished 7th chord is more dissonant and symmetrical.

Why does G diminished 7th sound unstable?

G diminished 7th contains two diminished 5th intervals, creating strong tension. The chord wants to resolve, usually to a chord a half step above one of its notes.