Modal RunsCm7b5 Chord (Half-Dim 7th)
Half-diminished 7th (m7♭5) is a diminished triad with a flat 7th instead of a double-flat 7th — root, flat 3rd, flat 5th, flat 7th. The notes of Cm7b5 are C, D#, F#, A#.
Moodier than min7, less violent than dim7 — it’s the ii chord in a minor-key ii-V-i, the sound of jazz standards leaning toward a minor resolution.
Cm7b5 voicings on guitar
Every playable, root-in-the-bass grip standard tuning offers, computed from the chord’s own formula — not a fixed shape library.
Follow it with a dominant 7th a 4th up, then a minor chord — that’s the minor ii-V-i, and half-dim7 is doing the setup work.
Formula and intervals
R - b3 - b5 - b7 — 4 notes.
Scales that fit Cm7b5
Every scale below contains all of this chord’s notes — safe territory to improvise in over it.
Also compatible: Blues, Altered (Super Locrian), Diminished (HW).