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

G♭m7♭5 contains G♭, B♭♭, D♭♭ and F♭. A diminished triad with the minor seventh added on top. G♭ is a black key; B♭♭, D♭♭ and F♭ are white.

- Canonical page: https://piano.org/chords/half-diminished/g-flat/
- Entity: chord:half-diminished-7th:g-flat
- 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: G♭m7♭5, Gbm7b5, 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 2 on G♭, finger 3 on B♭♭, finger 4 on D♭♭, finger 5 on F♭. The left hand mirrors it.
Right hand 2-3-4-5, left hand 5-4-3-2. Source: piano.org fingering method v1.

## Inversions

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

## Voicings (10)

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

## Diatonic function by key

| Key | Roman numeral | Function |
| --- | --- | --- |
| E minor | iim7♭5 | Predominant |
| G major | viim7♭5 | Dominant function |

Classification system: common-practice functional harmony.

## Progressions (2)

| Progression | Key | Role | Sequence | Voice leading |
| --- | --- | --- | --- | --- |
| ii, v, i | E minor | iim7♭5 | F♯m7♭5 to Bm7 to Em7 | G♭m7♭5 opens the phrase |
| vii, I | G major | viim7♭5 | F♯m7♭5 to Gmaj7 | G♭m7♭5 opens the phrase |

## One-edit neighbors

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

## Set theory

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

## Frequencies (close root position)

| Note | MIDI | Frequency |
| --- | --- | --- |
| G♭3 | 54 | 185.00 Hz |
| B♭♭3 | 57 | 220.00 Hz |
| D♭♭4 | 60 | 261.63 Hz |
| F♭4 | 64 | 329.63 Hz |

## Questions and answers

### What notes are in G♭m7♭5?

G♭m7♭5 contains G♭, B♭♭, D♭♭ and F♭. The formula is 1, ♭3, ♭5, ♭7.

### How do you play G♭m7♭5 on piano?

Play G♭, B♭♭, D♭♭ and F♭ together. Right hand fingers 2, 3, 4, 5; left hand 5, 4, 3, 2. G♭ is a black key; B♭♭, D♭♭ and F♭ are white.

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

4 positions: root position G♭ B♭♭ D♭♭ F♭, G♭m7♭5/B♭♭, G♭m7♭5/D♭♭, G♭m7♭5/F♭.

### What keys contain G♭m7♭5?

2: iim7♭5 in E minor, viim7♭5 in G major.

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

Drops F♭. 3 of the notes are shared.

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

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

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

From G♭3 at A440 in 12-TET: 185.00, 220.00, 261.63, 329.63 Hz.

### What is the set class of G♭m7♭5?

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

### How do I transpose G♭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 F♯m7♭5 the same as G♭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:g-flat
Last reviewed: 2026-08-12