# G Half Diminished 7th piano chord (Gm7♭5)

Gm7♭5 contains G, B♭, D♭ and F. A diminished triad with the minor seventh added on top. B♭ and D♭ are black keys; G and F are white.

- Canonical page: https://piano.org/chords/half-diminished/g/
- Entity: chord:half-diminished-7th:g
- Notes: G B♭ D♭ F
- Formula: 1 ♭3 ♭5 ♭7
- Intervals from root: P1, m3, TT, m7
- Interval stack (semitones): 3 3 4
- Also written: Gm7♭5, Gm7b5, G half diminished 7th
- Parameters: A440, 12-TET, 165 mm octave, spans centre to centre

## Construction

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

## Fingering

Rest your right hand over the notes with finger 1 on G, finger 2 on B♭, finger 3 on D♭, finger 5 on F. 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 | G | G3 B♭3 D♭4 F4 | 7 | 10 st, 138 mm |
| First inversion (Gm7♭5/B♭) | B♭ | B♭3 D♭4 F4 G4 | 6/5 | 9 st, 124 mm |
| Second inversion (Gm7♭5/D♭) | D♭ | D♭4 F4 G4 B♭4 | 4/3 | 9 st, 124 mm |
| Third inversion (Gm7♭5/F) | F | F4 G4 B♭4 D♭5 | 4/2 | 8 st, 110 mm |

## Voicings (10)

| Voicing | Notes | Span | Relation | Omits or adds |
| --- | --- | --- | --- | --- |
| Close, root position | G3 B♭3 D♭4 F4 | 10 st, 138 mm | identical | none |
| Close, first inversion | B♭3 D♭4 F4 G4 | 9 st, 124 mm | identical | none |
| Close, second inversion | D♭4 F4 G4 B♭4 | 9 st, 124 mm | identical | none |
| Close, third inversion | F4 G4 B♭4 D♭5 | 8 st, 110 mm | identical | none |
| Drop 2 | D♭3 G3 B♭3 F4 | 16 st, 220 mm | identical | none |
| Drop 3 | B♭2 G3 D♭4 F4 | 19 st, 261 mm | identical | none |
| Drop 2 and 4 | G2 D♭3 B♭3 F4 | 22 st, 303 mm | identical | none |
| Shell, root ♭7 ♭3 | G2 F3 B♭3 | 15 st, 206 mm | subset | omits D♭ |
| Guide tones, ♭3 and ♭7 | B♭3 F4 | 7 st, 96 mm | subset | omits G and D♭ |
| Rootless close | B♭3 D♭4 F4 | 7 st, 96 mm | subset | omits G |

## Diatonic function by key

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

Classification system: common-practice functional harmony.

## Progressions (2)

| Progression | Key | Role | Sequence | Voice leading |
| --- | --- | --- | --- | --- |
| ii, v, i | F minor | iim7♭5 | Gm7♭5 to Cm7 to Fm7 | Gm7♭5 opens the phrase |
| vii, I | A♭ major | viim7♭5 | Gm7♭5 to A♭maj7 | Gm7♭5 opens the phrase |

## One-edit neighbors

| Becomes | Edit | Changes | Common tones |
| --- | --- | --- | --- |
| Gdim | 1 ♭3 ♭5 | drops F | 3 |
| Gm7 | 1 ♭3 5 ♭7 | D♭ becomes D | 3 |
| Gdim7 | 1 ♭3 ♭5 ♭♭7 | F becomes F♭ | 3 |
| Gm9 | 1 ♭3 5 ♭7 9 | D♭ becomes D, A | 3 |
| Gm | 1 ♭3 5 | D♭, F becomes D | 2 |
| G7 | 1 3 5 ♭7 | B♭, D♭ becomes B, D | 2 |
| GmMaj7 | 1 ♭3 5 7 | D♭, F becomes D, F♯ | 2 |
| Gaug7 | 1 3 ♯5 ♭7 | B♭, D♭ becomes B, D♯ | 2 |
| G7sus4 | 1 4 5 ♭7 | B♭, D♭ becomes C, D | 2 |
| Gm6 | 1 ♭3 5 6 | D♭, F becomes D, E | 2 |

## Set theory

- Absolute pitch classes: {7, 10, 1, 5}
- Relative pitch classes: [0, 3, 6, 10]
- Normal order: [5, 7, 10, 1]
- Prime form: (0258)
- Forte number: 4-27
- Interval vector: <012111>

## Frequencies (close root position)

| Note | MIDI | Frequency |
| --- | --- | --- |
| G3 | 55 | 196.00 Hz |
| B♭3 | 58 | 233.08 Hz |
| D♭4 | 61 | 277.18 Hz |
| F4 | 65 | 349.23 Hz |

## Questions and answers

### What notes are in Gm7♭5?

Gm7♭5 contains G, B♭, D♭ and F. The formula is 1, ♭3, ♭5, ♭7.

### How do you play Gm7♭5 on piano?

Play G, B♭, D♭ and F together. Right hand fingers 1, 2, 3, 5; left hand 5, 3, 2, 1. B♭ and D♭ are black keys; G and F are white.

### What are the inversions of Gm7♭5?

4 positions: root position G B♭ D♭ F, Gm7♭5/B♭, Gm7♭5/D♭, Gm7♭5/F.

### What keys contain Gm7♭5?

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

### What is the difference between Gm7♭5 and Gdim?

Drops F. 3 of the notes are shared.

### What is an easy Gm7♭5 for small hands?

The guide tones, ♭3 and ♭7 voicing, B♭3 F4, spans 7 semitones or about 96 mm.

### What are the frequencies of Gm7♭5?

From G3 at A440 in 12-TET: 196.00, 233.08, 277.18, 349.23 Hz.

### What is the set class of Gm7♭5?

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

### How do I transpose Gm7♭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.

## 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:g
Last reviewed: 2026-08-12