Chord sequence
Gm7♭5 G♭7♯11
In every key
Four-note rootless voicings in their two forms, with the 3rd or the 7th on the bottom, played over the root.
Heard in Ab major
Over Gm7b5 · viiø7
Mode 7 of Major
Over Gb7#11 · ♭VII7♯11
Mode 4 of Melodic Minor