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New Released in April 2026

C Half-Diminished Chord on Piano (Cm7b5)

C half-diminished 7th (Cm7b5) is spelled C - Eb - Gb - Bb. It sounds like Cdim with an extra Bb, the note that gives it its dark, unresolved colour. Here you will find its inversions, both hands and the chords it belongs with.

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Cm7b5 C Eb Gb Bb

C half-diminished 7th chord inversions

In the 3rd inversion Bb is the lowest note: the seventh in the bass.

Cm7b5 C Eb Gb Bb

Root position: C Eb Gb Bb

Cm7b5 Eb Gb Bb C

1st inversion: Eb Gb Bb C

Cm7b5 Gb Bb C Eb

2nd inversion: Gb Bb C Eb

Cm7b5 Bb C Eb Gb

3rd inversion: Bb C Eb Gb

How to play Cm7b5 on the piano

HandCEbGbBb
Right hand1 (thumb)235 (little)
Left hand5 (little)321 (thumb)

Too much stretch? Play C alone in the left hand and Eb Gb Bb in the right.

Cm7b5 without the third

Cm7b5 C Gb Bb

Here keep the flat fifth: C Gb Bb, root, b5 and seventh. The b5 is what separates Cm7b5 from Cm7, so the third is the note to leave out.

How Cm7b5 differs from the other 7th chords on C

One note changes and the chord gets a new name.

ChordNotesWhat changes
C7 C E G Bbmajor 3rd, minor 7th
Cmaj7 C E G Bmajor 3rd, major 7th
Cm7 C Eb G Bbminor 3rd, minor 7th
Cm7b5 C Eb Gb Bbminor 3rd, flat 5th, minor 7th
Cdim7 C Eb Gb Bbbminor 3rd, flat 5th, 7th one key lower again

Cm7b5 in keys and progressions

  • Cm7b5 is the iiø7 of Bb minor and the viiø7 of Db major.
  • In a minor ii-V-i it opens the cadence: Cm7b5 → F7 → Bbm.
  • Cm7b5 has the same notes as Ebm6 (Eb Gb Bb C): with C in the bass it is Cm7b5, with Eb in the bass it is Ebm6.

ii-V-i: Cm7b5 → F7 → Bbm

Learning Cm7b5 step by step

  1. Play C, Eb, Gb, Bb slowly in root position and say "Cm7b5" each time.
  2. Climb the four positions: C Eb Gb Bb, then Eb Gb Bb C, Gb Bb C Eb and Bb C Eb Gb, and back down.
  3. Play it in its ii-V-I, Cm7b5 → F7 → Bbm, four beats per chord.
  4. Then mix it with chords you already know, in an order you do not choose: that is where it sticks.

A few minutes every day on Cm7b5 beat one long session a week.

ChordRunner showing a chord block while hands play the piano

Make Cm7b5 automatic

In ChordRunner Cm7b5 and every other chord ride towards your runner: play them in time. MIDI keyboard or microphone, both work.

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Common questions

How do you play Cm7b5 on the piano?

Press C, Eb, Gb, Bb together. Right hand 1, 2, 3, 5 with the thumb on C; any octave and any order of those notes is still Cm7b5.

What are the inversions of Cm7b5?

Root position C Eb Gb Bb, 1st inversion Eb Gb Bb C, 2nd inversion Gb Bb C Eb and 3rd inversion Bb C Eb Gb. Every position is still Cm7b5.

Where does Cm7b5 go?

Cm7b5 is the iiø7 of Bb minor and the viiø7 of Db major. In a minor ii-V-i it opens the cadence: Cm7b5 → F7 → Bbm.

Can I practise Cm7b5 with a MIDI keyboard?

Yes. In ChordRunner a USB MIDI keyboard is detected automatically, and an acoustic piano works through the microphone. Cm7b5 counts in any inversion, as long as C, Eb, Gb, Bb sound together.

Your instrument is the controller.

ChordRunner is a browser game that teaches piano and guitar chords: a chord appears on screen, you play it on a real instrument, and your runner jumps. MIDI keyboard or microphone, both work.

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