Sevenths
G♭ half-diminished 7th chord
Dark and unresolved; often the ii chord in a minor key.
G♭m7♭5 is the viiø7 chord in G major. In minor keys: iiø7 in E minor.
- Notes
- G♭B𝄫D𝄫F♭
- Formula
- 1♭3♭5♭7
- Built from
- root · minor 3rd · diminished 5th · minor 7th
How to play G♭m7♭5
About the G♭ half-diminished 7th chord
Playing it
On guitar, G♭m7♭5 has an open-position shape, 202210, using four fingers alongside the open strings.
On piano, G♭m7♭5 has one black key (G♭) and three white keys.
On ukulele the usual G♭m7♭5 shape is 2423, using four fingers.
Related chords
Take away the root and the other three notes form B𝄫m (B𝄫 D𝄫 F♭) — so you can think of G♭m7♭5 as B𝄫m with G♭ added underneath.
G♭m7♭5 contains exactly the same notes as Am6. Which name fits depends on which note is in the bass and what key you’re in.
Move a single note and G♭m7♭5 becomes a different chord: raise D𝄫 to D♭ for G♭m7, drop the F♭ for G♭dim and lower F♭ to F𝄫 for G♭dim7.
Where you’ll hear it
Notice the B𝄫 in G♭m7♭5 (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.
