# G Diminished piano chord (Gdim) Gdim contains G, B♭ and D♭. Two stacked minor thirds. B♭ and D♭ are black keys; G is white. - Canonical page: https://piano.org/chords/diminished/g/ - Entity: chord:diminished:g - Notes: G B♭ D♭ - Formula: 1 ♭3 ♭5 - Intervals from root: P1, m3, TT - Interval stack (semitones): 3 3 - Also written: Gdim, Gdim, 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 | G3 B♭3 D♭4 | 5/3 | 6 st, 83 mm | | First inversion (Gdim/B♭) | B♭ | B♭3 D♭4 G4 | 6/3 | 9 st, 124 mm | | Second inversion (Gdim/D♭) | D♭ | D♭4 G4 B♭4 | 6/4 | 9 st, 124 mm | ## Voicings (5) | Voicing | Notes | Span | Relation | Omits or adds | | --- | --- | --- | --- | --- | | Close, root position | G3 B♭3 D♭4 | 6 st, 83 mm | identical | none | | Close, first inversion | B♭3 D♭4 G4 | 9 st, 124 mm | identical | none | | Close, second inversion | D♭4 G4 B♭4 | 9 st, 124 mm | identical | none | | Open, fifth on top | G2 D♭3 B♭3 | 15 st, 206 mm | identical | none | | Root and third only | G3 B♭3 | 3 st, 41 mm | subset | omits D♭ | ## Diatonic function by key | Key | Roman numeral | Function | | --- | --- | --- | | F minor | ii° | Predominant | | A♭ major | vii° | Dominant function | Classification system: common-practice functional harmony. ## Progressions (2) | Progression | Key | Role | Sequence | Voice leading | | --- | --- | --- | --- | --- | | ii°, v, i | F minor | ii° | Gdim to Cm to Fm | Gdim opens the phrase | | vii°, I | A♭ major | vii° | Gdim to A♭ | Gdim opens the phrase | ## One-edit neighbors | Becomes | Edit | Changes | Common tones | | --- | --- | --- | --- | | Gm7♭5 | 1 ♭3 ♭5 ♭7 | adds F | 3 | | Gdim7 | 1 ♭3 ♭5 ♭♭7 | adds F♭ | 3 | | Gm | 1 ♭3 5 | D♭ becomes D | 2 | | Gm7 | 1 ♭3 5 ♭7 | D♭ becomes D, F | 2 | | GmMaj7 | 1 ♭3 5 7 | D♭ becomes D, F♯ | 2 | | Gm6 | 1 ♭3 5 6 | D♭ becomes D, E | 2 | | G | 1 3 5 | B♭, D♭ becomes B, D | 1 | | Gaug | 1 3 ♯5 | B♭, D♭ becomes B, D♯ | 1 | | Gsus2 | 1 2 5 | B♭, D♭ becomes A, D | 1 | | Gsus4 | 1 4 5 | B♭, D♭ becomes C, D | 1 | ## Set theory - Absolute pitch classes: {7, 10, 1} - Relative pitch classes: [0, 3, 6] - Normal order: [7, 10, 1] - Prime form: (036) - Forte number: 3-10 - Interval vector: <002001> ## Frequencies (close root position) | Note | MIDI | Frequency | | --- | --- | --- | | G3 | 55 | 196.00 Hz | | B♭3 | 58 | 233.08 Hz | | D♭4 | 61 | 277.18 Hz | ## Questions and answers ### What notes are in Gdim? Gdim contains G, B♭ and D♭. The formula is 1, ♭3, ♭5. ### How do you play Gdim on piano? Play G, B♭ and D♭ together. Right hand fingers 1, 3, 5; left hand 5, 3, 1. B♭ and D♭ are black keys; G is white. ### What are the inversions of Gdim? 3 positions: root position G B♭ D♭, Gdim/B♭, Gdim/D♭. ### What keys contain Gdim? 2: ii° in F minor, vii° in A♭ major. ### What is the difference between Gdim and Gm7♭5? Adds F. 3 of the notes are shared. ### What is an easy Gdim for small hands? The root and third only voicing, G3 B♭3, spans 3 semitones or about 41 mm. ### What are the frequencies of Gdim? From G3 at A440 in 12-TET: 196.00, 233.08, 277.18 Hz. ### What is the set class of Gdim? Prime form (036), Forte 3-10, interval vector <002001>. ### How do I transpose Gdim to another key? Keep the 1, ♭3, ♭5 formula on the new root. Cdim is C, E♭, G♭; C♯dim is C♯, E, G. ## 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 Last reviewed: 2026-08-12