# C♭ Half Diminished 7th piano chord (C♭m7♭5)

C♭m7♭5 contains C♭, E♭♭, G♭♭ and B♭♭. A diminished triad with the minor seventh added on top. Every note is a white key.

- Canonical page: https://piano.org/chords/half-diminished/c-flat/
- Entity: chord:half-diminished-7th:c-flat
- Notes: C♭ E♭♭ G♭♭ B♭♭
- Formula: 1 ♭3 ♭5 ♭7
- Intervals from root: P1, m3, TT, m7
- Interval stack (semitones): 3 3 4
- Also written: C♭m7♭5, Cbm7b5, C♭ half diminished 7th
- Parameters: A440, 12-TET, 165 mm octave, spans centre to centre

## Construction

| Degree | Note | Interval from root | Semitones |
| --- | --- | --- | --- |
| 1 | C♭ | Perfect unison | 0 |
| ♭3 | E♭♭ | Minor third | 3 |
| ♭5 | G♭♭ | Tritone | 6 |
| ♭7 | B♭♭ | Minor seventh | 10 |

## Fingering

Rest your right hand over the notes with finger 1 on C♭, finger 2 on E♭♭, finger 3 on G♭♭, finger 5 on B♭♭. The left hand mirrors it.
Right hand 1-2-3-5, left hand 5-3-2-1. Source: piano.org fingering method v1.

## Inversions

| Position | Bass | Notes in order | Figured bass | Span |
| --- | --- | --- | --- | --- |
| Root position | C♭ | C♭3 E♭♭4 G♭♭4 B♭♭4 | 7 | 10 st, 138 mm |
| First inversion (C♭m7♭5/E♭♭) | E♭♭ | E♭♭4 G♭♭4 B♭♭4 C♭4 | 6/5 | 9 st, 124 mm |
| Second inversion (C♭m7♭5/G♭♭) | G♭♭ | G♭♭4 B♭♭4 C♭4 E♭♭5 | 4/3 | 9 st, 124 mm |
| Third inversion (C♭m7♭5/B♭♭) | B♭♭ | B♭♭4 C♭4 E♭♭5 G♭♭5 | 4/2 | 8 st, 110 mm |

## Voicings (10)

| Voicing | Notes | Span | Relation | Omits or adds |
| --- | --- | --- | --- | --- |
| Close, root position | C♭3 E♭♭4 G♭♭4 B♭♭4 | 10 st, 138 mm | identical | none |
| Close, first inversion | E♭♭4 G♭♭4 B♭♭4 C♭4 | 9 st, 124 mm | identical | none |
| Close, second inversion | G♭♭4 B♭♭4 C♭4 E♭♭5 | 9 st, 124 mm | identical | none |
| Close, third inversion | B♭♭4 C♭4 E♭♭5 G♭♭5 | 8 st, 110 mm | identical | none |
| Drop 2 | G♭♭3 C♭3 E♭♭4 B♭♭4 | 16 st, 220 mm | identical | none |
| Drop 3 | E♭♭3 C♭3 G♭♭4 B♭♭4 | 19 st, 261 mm | identical | none |
| Drop 2 and 4 | C♭2 G♭♭3 E♭♭4 B♭♭4 | 22 st, 303 mm | identical | none |
| Shell, root ♭7 ♭3 | C♭2 B♭♭3 E♭♭4 | 15 st, 206 mm | subset | omits G♭♭ |
| Guide tones, ♭3 and ♭7 | E♭♭4 B♭♭4 | 7 st, 96 mm | subset | omits C♭ and G♭♭ |
| Rootless close | E♭♭4 G♭♭4 B♭♭4 | 7 st, 96 mm | subset | omits C♭ |

## Diatonic function by key

| Key | Roman numeral | Function |
| --- | --- | --- |
| C major | viim7♭5 | Dominant function |
| A minor | iim7♭5 | Predominant |

Classification system: common-practice functional harmony.

## Progressions (2)

| Progression | Key | Role | Sequence | Voice leading |
| --- | --- | --- | --- | --- |
| vii, I | C major | viim7♭5 | Bm7♭5 to Cmaj7 | C♭m7♭5 opens the phrase |
| ii, v, i | A minor | iim7♭5 | Bm7♭5 to Em7 to Am7 | C♭m7♭5 opens the phrase |

## One-edit neighbors

| Becomes | Edit | Changes | Common tones |
| --- | --- | --- | --- |
| C♭dim | 1 ♭3 ♭5 | drops B♭♭ | 3 |
| C♭m7 | 1 ♭3 5 ♭7 | G♭♭ becomes G♭ | 3 |
| C♭dim7 | 1 ♭3 ♭5 ♭♭7 | B♭♭ becomes B♭♭♭ | 3 |
| C♭m9 | 1 ♭3 5 ♭7 9 | G♭♭ becomes G♭, D♭ | 3 |
| C♭m | 1 ♭3 5 | G♭♭, B♭♭ becomes G♭ | 2 |
| C♭7 | 1 3 5 ♭7 | E♭♭, G♭♭ becomes E♭, G♭ | 2 |
| C♭mMaj7 | 1 ♭3 5 7 | G♭♭, B♭♭ becomes G♭, B♭ | 2 |
| C♭aug7 | 1 3 ♯5 ♭7 | E♭♭, G♭♭ becomes E♭, G | 2 |
| C♭7sus4 | 1 4 5 ♭7 | E♭♭, G♭♭ becomes F♭, G♭ | 2 |
| C♭m6 | 1 ♭3 5 6 | G♭♭, B♭♭ becomes G♭, A♭ | 2 |

## Set theory

- Absolute pitch classes: {11, 2, 5, 9}
- Relative pitch classes: [0, 3, 6, 10]
- Normal order: [9, 11, 2, 5]
- Prime form: (0258)
- Forte number: 4-27
- Interval vector: <012111>

## Frequencies (close root position)

| Note | MIDI | Frequency |
| --- | --- | --- |
| C♭3 | 59 | 246.94 Hz |
| E♭♭4 | 62 | 293.66 Hz |
| G♭♭4 | 65 | 349.23 Hz |
| B♭♭4 | 69 | 440.00 Hz |

## Questions and answers

### What notes are in C♭m7♭5?

C♭m7♭5 contains C♭, E♭♭, G♭♭ and B♭♭. The formula is 1, ♭3, ♭5, ♭7.

### How do you play C♭m7♭5 on piano?

Play C♭, E♭♭, G♭♭ and B♭♭ together. Right hand fingers 1, 2, 3, 5; left hand 5, 3, 2, 1. Every note is a white key.

### What are the inversions of C♭m7♭5?

4 positions: root position C♭ E♭♭ G♭♭ B♭♭, C♭m7♭5/E♭♭, C♭m7♭5/G♭♭, C♭m7♭5/B♭♭.

### What keys contain C♭m7♭5?

2: viim7♭5 in C major, iim7♭5 in A minor.

### What is the difference between C♭m7♭5 and C♭dim?

Drops B♭♭. 3 of the notes are shared.

### What is an easy C♭m7♭5 for small hands?

The guide tones, ♭3 and ♭7 voicing, E♭♭4 B♭♭4, spans 7 semitones or about 96 mm.

### What are the frequencies of C♭m7♭5?

From C♭3 at A440 in 12-TET: 246.94, 293.66, 349.23, 440.00 Hz.

### What is the set class of C♭m7♭5?

Prime form (0258), Forte 4-27, interval vector &lt;012111&gt;.

### How do I transpose C♭m7♭5 to another key?

Keep the 1, ♭3, ♭5, ♭7 formula on the new root. Cm7♭5 is C, E♭, G♭, B♭; C♯m7♭5 is C♯, E, G, B.

### Is Bm7♭5 the same as C♭m7♭5?

Enharmonically yes: the same piano keys and the same sound, spelled differently.

## Provenance

Every derived value above is computed by the piano.org theory kernel from the root, the quality and the stated parameters. Nothing is hand-entered per chord.

Machine record: https://piano.org/api/knowledge/v1/entities/chord:half-diminished-7th:c-flat
Last reviewed: 2026-08-12