C half-diminished seventh

Cm7b5 Piano Voicings

Cm7b5, the half-diminished chord, is the ii chord of a B♭ minor ii-V-i. Its lowered fifth gives the tense, unresolved colour that defines minor-key jazz.

Drill Cm7b5 in all 12 keys

The notes in Cm7b5

  • C R
  • Eb ♭3
  • Gb ♭5
  • Bb ♭7

Cm7b5 voicings on piano

Each voicing is the exact shape the trainer drills. Press play to hear it — as a block chord or rolled note by note.

Root Position

C · Eb · Gb · Bb R · ♭3 · ♭5 · ♭7

Shell Voicing

C · Eb · Bb R · ♭3 · ♭7

Rootless A

Eb · Gb · Bb · D ♭3 · ♭5 · ♭7 · 9

Rootless B

Bb · D · Eb · Gb ♭7 · 9 · ♭3 · ♭5

Where Cm7b5 fits in a ii-V-I

Cm7b5, the half-diminished chord, is the ii chord of a B♭ minor ii-V-i. Its lowered fifth gives the tense, unresolved colour that defines minor-key jazz.

The fastest way to internalise Cm7b5 is to drill it in context across all 12 keys until the shape is automatic.

Practice the full ii-V-I progression

Cm7b5 — frequently asked questions

What notes are in Cm7b5?

Cm7b5 contains C, E♭, G♭ and B♭ — root, minor third, diminished (flat) fifth and flat seventh.

What is the difference between Cm7b5 and Cdim7?

Both lower the fifth, but Cm7b5 keeps a flat seventh (B♭) while Cdim7 uses a diminished seventh (B♭♭ / A), making the diminished chord fully symmetrical.