Sevenths
G♭ diminished 7th chord
Symmetrical and very tense — every note is a minor 3rd apart.
G♭dim7 is the vii°7 chord in G minor.
- Notes
- G♭B𝄫D𝄫F𝄫
- Formula
- 1♭3♭5𝄫7
- Built from
- root · minor 3rd · diminished 5th · diminished 7th
How to play G♭dim7
About the G♭ diminished 7th chord
Playing it
On guitar, G♭dim7 has an open-position shape, 20121x, using four fingers alongside the open strings. Don’t strum the high E string.
On piano, G♭dim7 has two black keys (G♭ and F𝄫) and two white keys.
On ukulele the usual G♭dim7 shape is 2323, using four fingers.
Related chords
Take away the root and the other three notes form B𝄫dim (B𝄫 D𝄫 F𝄫) — so you can think of G♭dim7 as B𝄫dim with G♭ added underneath.
G♭dim7 is symmetrical — its notes are evenly spaced — so Cdim7, E♭dim7 and Adim7 contain exactly the same notes. There are only three different-sounding diminished 7th chords in all.
Move a single note and G♭dim7 becomes a different chord: drop the F𝄫 for G♭dim, raise D𝄫 to D♭ for G♭m6 and raise F𝄫 to F♭ for G♭m7♭5.
Where you’ll hear it
Notice the B𝄫 in G♭dim7 (G♭ B𝄫 D𝄫 F𝄫): each note of the chord takes its own letter (G–B–D–F), so the minor 3rd has to be written B𝄫 rather than A — the same key on a piano, spelled to fit the chord.
