Sevenths
C half-diminished 7th chord
Dark and unresolved; often the ii chord in a minor key.
Cm7♭5 is the viiø7 chord in D♭ major. In minor keys: iiø7 in B♭ minor.
- Notes
- CE♭G♭B♭
- Formula
- 1♭3♭5♭7
- Built from
- root · minor 3rd · diminished 5th · minor 7th
How to play Cm7♭5
About the C half-diminished 7th chord
Playing it
On guitar, the usual Cm7♭5 shape is x3434x at the 3rd fret. It has no open strings, so it’s a movable shape — slide it along the neck for other half-diminished 7th chords. Don’t strum the low E and high E strings.
On piano, Cm7♭5 has three black keys (E♭, G♭ and B♭) and one white key.
On ukulele the usual Cm7♭5 shape is 3323, using four fingers.
Related chords
Take away the root and the other three notes form E♭m (E♭ G♭ B♭) — so you can think of Cm7♭5 as E♭m with C added underneath.
Cm7♭5 contains exactly the same notes as E♭m6. Which name fits depends on which note is in the bass and what key you’re in.
Move a single note and Cm7♭5 becomes a different chord: raise G♭ to G for Cm7, drop the B♭ for Cdim and lower B♭ to B𝄫 for Cdim7.
