Gdim7 guitar chord
An open string left ringing against a fretted grip. Because it costs no finger, it sounds a note the closed shape has none left for -- a tension on top, or a pedal root underneath. Either a familiar grip with open strings added, or a shape so sparse the open strings carry the chord. These belong to their key rather than to a shape, so D, A, G and E have many and Eb a handful.
- Tap a note to hear it
- Arrows change position
- Fingers, notes or intervals
- Play the chord
About Gdim7 — open string voicings
Gdim7 is G, Bb, Db and Fb — Gdim with a diminished seventh stacked on top.
It sounds suspenseful and rootless. Three stacked minor thirds divide the octave evenly, so the same four notes spell four dim7 chords and the shape repeats every three frets.
Gdim7 notes and formula
| G | Bb | Db | Fb |
|---|---|---|---|
| 1 | ♭3 | ♭5 | ♭♭7 |
Leading-tone or passing chord — it can resolve almost anywhere.
Also written G°7, Go7 or G diminished 7. The same chord either way; which spelling you meet depends on who wrote the chart.
How to play Gdim7
An open string left ringing against a fretted grip. It costs no finger, so it can sound a note the closed shape has none left for: a tension on top, or a pedal root underneath.
These belong to their key rather than to a shape: they cannot be moved up the neck. D, A, G and E have many; E♭ has a handful.
Gdim7 has 1 of them, only on strings 6-5-4-3-2-1, all of them at the 5th fret — all in one inversion, so the bass note never moves. The one to learn first is the Fb shape at the 5th fret, which is the easiest grip here.
Start with 31x320 — no barre and 1 open string. 2 of the 8 shapes here sit in open position. 2 of the 8 need a barre. Together they cover the neck from the 1st fret to the 15th.
| Frets | Where | Bass | Top | Hand |
|---|---|---|---|---|
| 31x320 | open position | G, root position | Fb | 1 open string |
| 3x2320 | open position | G, root position | Fb | 1 open string |
| 345353 | 3rd fret | G, root position | G | barred |
| xx5656 | 5th fret | G, root position | Bb | all fretted |
| xx8989 | 8th fret | Bb, 1st inversion | Db | all fretted |
| x-10-11-9-11-9 | 9th fret | G, root position | Db | all fretted |
| x-x-11-12-11-12 | 11th fret | Db, 2nd inversion | Fb | all fretted |
| 15-x-14-15-14-15 | 14th fret | G, root position | G | barred |
The same notes rebuilt from scratch give 6 shell, 14 drop 2 and 10 drop 3 voicings, each on its own page.
Tensions. A shell of Gdim7, root, third and seventh, leaves a string free, and the tones that belong over it are the 9 (A), the 11 (C), the b13 (Eb) and the maj7 (F#).
How to use Gdim7
A diminished seventh divides the octave evenly, so Gdim7 has no single root and no single destination: it can lead to C or to Ab, and it is the same four notes either way.
What to play over Gdim7
Every note of Gdim7 is in G diminished and G half-whole diminished.
Chords near Gdim7
Change one note of Gdim7 and you have Gdim (drop the sixth), Gm6 (the flat fifth becomes a fifth), Gm7b5 (the sixth becomes a flat seventh) or GmMaj7b5 (the sixth becomes a major seventh).
Gdim7 is a diminished chord — root, minor third, flat fifth. Diminished and half-diminished chords on every root.
On Gdim7’s sound and use this page follows Stefan Kostka, Dorothy Payne & Byron Almén, Tonal Harmony (McGraw-Hill, 8th ed., 2018). The shapes and the derived voicings come from different places, and both are explained in where the chords and the theory come from.