# G Diminished 7th piano chord (Gdim7) Gdim7 contains G, B♭, D♭ and F♭. Three stacked minor thirds. B♭ and D♭ are black keys; G and F♭ are white. - Canonical page: https://piano.org/chords/diminished-7th/g/ - Entity: chord:diminished-7th:g - Notes: G B♭ D♭ F♭ - Formula: 1 ♭3 ♭5 ♭♭7 - Intervals from root: P1, m3, TT, M6 - Interval stack (semitones): 3 3 3 - Also written: Gdim7, Gdim7, G 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♭ | Major sixth | 9 | ## 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 F♭4 | 7 | 9 st, 124 mm | | First inversion (Gdim7/B♭) | B♭ | B♭3 D♭4 F♭4 G4 | 6/5 | 9 st, 124 mm | | Second inversion (Gdim7/D♭) | D♭ | D♭4 F♭4 G4 B♭4 | 4/3 | 9 st, 124 mm | | Third inversion (Gdim7/F♭) | F♭ | F♭4 G4 B♭4 D♭5 | 4/2 | 9 st, 124 mm | ## Voicings (10) | Voicing | Notes | Span | Relation | Omits or adds | | --- | --- | --- | --- | --- | | Close, root position | G3 B♭3 D♭4 F♭4 | 9 st, 124 mm | identical | none | | Close, first inversion | B♭3 D♭4 F♭4 G4 | 9 st, 124 mm | identical | none | | Close, second inversion | D♭4 F♭4 G4 B♭4 | 9 st, 124 mm | identical | none | | Close, third inversion | F♭4 G4 B♭4 D♭5 | 9 st, 124 mm | identical | none | | Drop 2 | D♭3 G3 B♭3 F♭4 | 15 st, 206 mm | identical | none | | Drop 3 | B♭2 G3 D♭4 F♭4 | 18 st, 248 mm | identical | none | | Drop 2 and 4 | G2 D♭3 B♭3 F♭4 | 21 st, 289 mm | identical | none | | Shell, root ♭♭7 ♭3 | G2 F♭3 B♭3 | 15 st, 206 mm | subset | omits D♭ | | Guide tones, ♭3 and ♭♭7 | B♭3 F♭4 | 6 st, 83 mm | subset | omits G and D♭ | | Rootless close | B♭3 D♭4 F♭4 | 6 st, 83 mm | subset | omits G | ## One-edit neighbors | Becomes | Edit | Changes | Common tones | | --- | --- | --- | --- | | Gdim | 1 ♭3 ♭5 | drops F♭ | 3 | | Gm7♭5 | 1 ♭3 ♭5 ♭7 | F♭ becomes F | 3 | | Gm6 | 1 ♭3 5 6 | D♭ becomes D | 3 | | Gm | 1 ♭3 5 | D♭, F♭ becomes D | 2 | | Gm7 | 1 ♭3 5 ♭7 | D♭, F♭ becomes D, F | 2 | | GmMaj7 | 1 ♭3 5 7 | D♭, F♭ becomes D, F♯ | 2 | | G6 | 1 3 5 6 | B♭, D♭ becomes B, D | 2 | ## Set theory - Absolute pitch classes: {7, 10, 1, 4} - Relative pitch classes: [0, 3, 6, 9] - Normal order: [1, 4, 7, 10] - Prime form: (0369) - Forte number: 4-28 - Interval vector: <004002> ## Frequencies (close root position) | Note | MIDI | Frequency | | --- | --- | --- | | G3 | 55 | 196.00 Hz | | B♭3 | 58 | 233.08 Hz | | D♭4 | 61 | 277.18 Hz | | F♭4 | 64 | 329.63 Hz | ## Questions and answers ### What notes are in Gdim7? Gdim7 contains G, B♭, D♭ and F♭. The formula is 1, ♭3, ♭5, ♭♭7. ### How do you play Gdim7 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 Gdim7? 4 positions: root position G B♭ D♭ F♭, Gdim7/B♭, Gdim7/D♭, Gdim7/F♭. ### What is the difference between Gdim7 and Gdim? Drops F♭. 3 of the notes are shared. ### What is an easy Gdim7 for small hands? The guide tones, ♭3 and ♭♭7 voicing, B♭3 F♭4, spans 6 semitones or about 83 mm. ### What are the frequencies of Gdim7? From G3 at A440 in 12-TET: 196.00, 233.08, 277.18, 329.63 Hz. ### What is the set class of Gdim7? Prime form (0369), Forte 4-28, interval vector <004002>. ### How do I transpose Gdim7 to another key? Keep the 1, ♭3, ♭5, ♭♭7 formula on the new root. C♯dim7 is C♯, E, G, B♭; Ddim7 is D, F, A♭, C♭. ## 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-7th:g Last reviewed: 2026-08-12