The G-flat half-diminished seventh chord (abbreviated "Gbm7(b5) chord") is a four-note chord consisting of the notes G♭, B♭♭, D♭♭, and F♭. The chord is formed by lowering the fifth of a G-flat minor seventh chord a half step.
G-flat half-diminished seventh chord
G-flat half-diminished chord G-flat minor seventh flat five chord
G♭ B♭♭ D♭♭ F♭
1 ♭3 ♭5 ♭7
G♭ø G♭ø7 G♭m7b5 G♭–7(b5) G♭mi7(b5) G♭min7(b5)
Tetrad (four-note chord)