Chord · C Half-Diminished 7th (m7♭5)
Cm7♭5 Chord
Cm7♭5 is C, Eb, Gb and Bb — the ii in a minor ii-V-i.
Cm7♭5 on every instrument
The same 4 notes, 6 sets of hands. Open a diagram for alternate shapes, audio and the mistakes to avoid.
What Cm7♭5 is made of
Cm7b5 (C half diminished seventh) is built from the notes C, Eb, Gb, Bb, with the interval pattern 1, b3, b5, b7.
Stack 1, b3, b5 and b7 on a root of C and you get C, Eb, Gb and Bb. That interval recipe is what makes the chord a half diminished seventh chord — move the same shape to another root and the character travels with it, which is why Dm7♭5 sounds like a transposed Cm7♭5.
Half-Diminished 7th (m7♭5): The ii in a minor ii-V-i.
Spelling: the notes above are written the way a score would write them, not simplified to the nearest piano key. That is why this chord is spelled with E♭ rather than its enharmonic equivalent.
Keys that contain Cm7♭5
All 4 notes sit inside the scale of 4 keys. The roman numeral marks the degree the chord is rooted on.
Other chords on C
Same root, different colour.
The same half diminished seventh shape, moved
The identical interval recipe, built on other roots.
Questions people ask about Cm7b5
- What notes are in the Cm7b5 chord?
- Cm7b5 is made of C, Eb, Gb and Bb — the 1, b3, b5 and b7 degrees of a half diminished seventh chord built on C.
- What keys use the Cm7b5 chord?
- Every note of Cm7b5 belongs to 4 keys: Db Major (vii°), C# Major (vii°), Bb Minor (ii°), A# Minor (ii°). The roman numeral is the scale degree the chord is rooted on.
- How do you play Cm7b5 on guitar and piano?
- This page shows Cm7b5 on guitar, piano, ukulele, bass, mandolin and banjo — 9 voicings in total. Each diagram links to the full instrument page with alternate shapes, audio and common mistakes.
Learn the theory behind it
Why Cm7♭5 behaves the way it does — the guides that explain the chord instead of just spelling it.