# G♭ Diminished piano chord (G♭dim)

G♭dim contains G♭, B♭♭ and D♭♭. Two stacked minor thirds. G♭ is a black key; B♭♭ and D♭♭ are white.

- Canonical page: https://piano.org/chords/diminished/g-flat/
- Entity: chord:diminished:g-flat
- Notes: G♭ B♭♭ D♭♭
- Formula: 1 ♭3 ♭5
- Intervals from root: P1, m3, TT
- Interval stack (semitones): 3 3
- Also written: G♭dim, Gbdim, G♭ diminished
- 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 |

## Fingering

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

## Inversions

| Position | Bass | Notes in order | Figured bass | Span |
| --- | --- | --- | --- | --- |
| Root position | G♭ | G♭3 B♭♭3 D♭♭4 | 5/3 | 6 st, 83 mm |
| First inversion (G♭dim/B♭♭) | B♭♭ | B♭♭3 D♭♭4 G♭4 | 6/3 | 9 st, 124 mm |
| Second inversion (G♭dim/D♭♭) | D♭♭ | D♭♭4 G♭4 B♭♭4 | 6/4 | 9 st, 124 mm |

## Voicings (5)

| Voicing | Notes | Span | Relation | Omits or adds |
| --- | --- | --- | --- | --- |
| Close, root position | G♭3 B♭♭3 D♭♭4 | 6 st, 83 mm | identical | none |
| Close, first inversion | B♭♭3 D♭♭4 G♭4 | 9 st, 124 mm | identical | none |
| Close, second inversion | D♭♭4 G♭4 B♭♭4 | 9 st, 124 mm | identical | none |
| Open, fifth on top | G♭2 D♭♭3 B♭♭3 | 15 st, 206 mm | identical | none |
| Root and third only | G♭3 B♭♭3 | 3 st, 41 mm | subset | omits D♭♭ |

## Diatonic function by key

| Key | Roman numeral | Function |
| --- | --- | --- |
| E minor | ii° | Predominant |
| G major | vii° | Dominant function |

Classification system: common-practice functional harmony.

## Progressions (2)

| Progression | Key | Role | Sequence | Voice leading |
| --- | --- | --- | --- | --- |
| ii°, v, i | E minor | ii° | F♯dim to Bm to Em | G♭dim opens the phrase |
| vii°, I | G major | vii° | F♯dim to G | G♭dim opens the phrase |

## One-edit neighbors

| Becomes | Edit | Changes | Common tones |
| --- | --- | --- | --- |
| G♭m7♭5 | 1 ♭3 ♭5 ♭7 | adds F♭ | 3 |
| G♭dim7 | 1 ♭3 ♭5 ♭♭7 | adds F♭♭ | 3 |
| G♭m | 1 ♭3 5 | D♭♭ becomes D♭ | 2 |
| G♭m7 | 1 ♭3 5 ♭7 | D♭♭ becomes D♭, F♭ | 2 |
| G♭mMaj7 | 1 ♭3 5 7 | D♭♭ becomes D♭, F | 2 |
| G♭m6 | 1 ♭3 5 6 | D♭♭ becomes D♭, E♭ | 2 |
| G♭ | 1 3 5 | B♭♭, D♭♭ becomes B♭, D♭ | 1 |
| G♭aug | 1 3 ♯5 | B♭♭, D♭♭ becomes B♭, D | 1 |
| G♭sus2 | 1 2 5 | B♭♭, D♭♭ becomes A♭, D♭ | 1 |
| G♭sus4 | 1 4 5 | B♭♭, D♭♭ becomes C♭, D♭ | 1 |

## Set theory

- Absolute pitch classes: {6, 9, 0}
- Relative pitch classes: [0, 3, 6]
- Normal order: [6, 9, 0]
- Prime form: (036)
- Forte number: 3-10
- Interval vector: <002001>

## 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 |

## Questions and answers

### What notes are in G♭dim?

G♭dim contains G♭, B♭♭ and D♭♭. The formula is 1, ♭3, ♭5.

### How do you play G♭dim on piano?

Play G♭, B♭♭ and D♭♭ together. Right hand fingers 1, 3, 5; left hand 5, 3, 1. G♭ is a black key; B♭♭ and D♭♭ are white.

### What are the inversions of G♭dim?

3 positions: root position G♭ B♭♭ D♭♭, G♭dim/B♭♭, G♭dim/D♭♭.

### What keys contain G♭dim?

2: ii° in E minor, vii° in G major.

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

Adds F♭. 3 of the notes are shared.

### What is an easy G♭dim for small hands?

The root and third only voicing, G♭3 B♭♭3, spans 3 semitones or about 41 mm.

### What are the frequencies of G♭dim?

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

### What is the set class of G♭dim?

Prime form (036), Forte 3-10, interval vector &lt;002001&gt;.

### How do I transpose G♭dim to another key?

Keep the 1, ♭3, ♭5 formula on the new root. Cdim is C, E♭, G♭; C♯dim is C♯, E, G.

### Is F♯dim the same as G♭dim?

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:diminished:g-flat
Last reviewed: 2026-08-12