C Half-diminished
Cm7♭5
Notes
C · E♭ · G♭ · B♭
Intervals
- RootC (1P)
- Minor 3rdE♭ (3m)
- Diminished 5thG♭ (5d)
- Minor 7thB♭ (7m)
Fretboard
Adjust labels, frets, and palette in the interactive view.
Voicings & shapes
Drop-2 voicings (12)
Drop-3 voicings (8)
About
The C half-diminished (C–E♭–G♭–B♭), also written Cø7, is the naturally occurring chord on the seventh degree of a major scale and on the second degree of a natural minor scale. Its primary role in jazz is as the ii chord in a minor ii–V–i: Cm7♭5 → F7 → B♭m. The G♭ is the defining color tone — without it, the chord collapses to a plain Cm7. The 3rd and ♭7 together establish the minor seventh quality. On guitar, the fifth is essential and should not be omitted, since the ♭5 is precisely what distinguishes this chord. Compared to Cdim7, m7♭5 is more grounded due to the natural (rather than doubly-flatted) seventh, giving it a somber but less frantic character.
Chord diagrams
C Half-diminished voicing charts — tap a sheet to open it full size to save or print.
Similar chords
Chords sharing two or more notes with this one, ranked by overlap.
Scales containing this chord
- C Blues (deg 1)
- C Locrian (I)
- A♭ Mixolydian (III)
- B♭ Diminished (deg 2)
- B♭ Harmonic Minor (II)
- B♭ Natural Minor (II)
- D♭ Diminished (deg 8)
- D♭ Major (VII)
- D♭ Melodic Minor (VII)
- E Diminished (deg 6)
- E♭ Dorian (VI)
- E♭ Melodic Minor (VI)
- F Phrygian (V)
- F♯ Lydian (IV)
- G Diminished (deg 4)
- G Harmonic Minor (IV)
Scales whose notes include every chord tone. The Roman numeral (or scale degree) marks the chord root’s position in the scale.