Gdim7: G Diminished 7th Piano Chord

Root position: either hand, fingers low note to high
Hand	Notes	Fingers
Right	G, B♭, D♭, F♭	1-2-3-5
Left	G, B♭, D♭, F♭	5-3-2-1

Scale degree, note, and interval measured from the root.
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

Construction

G Diminished 7th = Root + Minor 3rd + Diminished 5th + Major 6th = G, B♭, D♭, F♭

Note	Interval	Degree
G	Root	1
B♭	Minor 3rd	♭3
D♭	Diminished 5th	♭5
F♭	Major 6th	6

Fingering

Note	Key color	Right hand	Left hand
G	white	thumb (1)	little finger (5)
B♭	black	index finger (2)	middle finger (3)
D♭	black	middle finger (3)	index finger (2)
F♭	white	little finger (5)	thumb (1)

Right hand: thumb (1) on G, index finger (2) on B♭, middle finger (3) on D♭, little finger (5) on F♭.

Left hand: little finger (5) on G, middle finger (3) on B♭, index finger (2) on D♭, thumb (1) on F♭.

G Diminished 7th Inversions

Root position
G – B♭ – D♭ – F♭
1st inversion (Gdim7/B♭)
B♭ – D♭ – F♭ – G
2nd inversion (Gdim7/D♭)
D♭ – F♭ – G – B♭
3rd inversion (Gdim7/F♭)
F♭ – G – B♭ – D♭

Key Signature

A Diminished 7th chord is built from symmetrical or ambiguous intervals, so it doesn't belong to a single key and has no key signature of its own.

Chords in the Key of G Major

These are the triads built on each degree of G Major:

I — G Major (major)

Degree	Numeral	Chord	Quality
1	I	G Major	Major
2	ii	A Minor	Minor
3	iii	B Minor	Minor
4	IV	C Major	Major
5	V	D Major	Major
6	vi	E Minor	Minor
7	vii°	F♯ Diminished	Diminished

Same Notes, Other Names

The notes G – B♭ – D♭ – F♭ aren’t exclusive to this chord. Depending on which note is the bass and how the chord functions, the same pitches also spell the following:

B♭ Diminished 7th→D♭ Diminished 7th→E Diminished 7th→

G Diminished 7th : Frequently Asked Questions

What is the G Diminished 7th chord on piano?

The G Diminished 7th chord contains the notes G – B♭ – D♭ – F♭. On piano, play these notes together to sound the chord.

What notes are in the G Diminished 7th chord?

The G Diminished 7th chord (Gdim7) contains four notes: G (root), Bb (minor third), Db (diminished fifth), and Fb (diminished seventh, enharmonically E). All four notes are spaced exactly 3 semitones apart.

How does G Diminished 7th differ from G Diminished?

G Diminished is a three-note triad (G, Bb, Db). G Diminished 7th adds Fb/E as the diminished seventh, completing the symmetrical four-note structure.

Why is the Diminished 7th chord symmetrical?

Gdim7 contains the same pitches as Bbdim7, Dbdim7, and Edim7: all inversions of the same four notes. Only three unique dim7 chords exist in total.

How is G Diminished 7th used in music?

Gdim7 functions as the vii°7 of Ab, resolving up by half step to Ab Major. It is one of the most commonly used dim7 chords because Ab Major is a popular key for vocalists and jazz. Gdim7 also passes chromatically between G and Ab chords.

What songs use Diminished 7th chords?

Diminished 7th chords appear in Michelle (Beatles), throughout Chopin and Beethoven, and in jazz standards. Gdim7 specifically appears as the leading-tone chord in Ab Major, one of the most common keys in R&B and jazz.

How many unique Diminished 7th chords exist?

Only three. Gdim7 shares its notes with Bbdim7, Dbdim7, and Edim7. The other two unique groups are Cdim7 and Ddim7.

G Diminished 7th in detail

Exact

Every pitch class is present and nothing outside the chord is added.

Type	Notes	Semitones	Span	Omissions and additions	Set relation
Close, root position	G3 B♭3 D♭4 F♭4	9	124 mm	none	identical
Close, first inversion	B♭3 D♭4 F♭4 G4	9	124 mm	none	identical
Close, second inversion	D♭4 F♭4 G4 B♭4	9	124 mm	none	identical
Close, third inversion	F♭4 G4 B♭4 D♭5	9	124 mm	none	identical
Drop 2	D♭3 G3 B♭3 F♭4	15	206 mm	none	identical
Drop 3	B♭2 G3 D♭4 F♭4	18	248 mm	none	identical
Drop 2 and 4	G2 D♭3 B♭3 F♭4	21	289 mm	none	identical

Reduced

A subset of the pitch classes: the identity is incomplete rather than altered.

Type	Notes	Semitones	Span	Omissions and additions	Set relation
Shell, root ♭♭7 ♭3	G2 F♭3 B♭3	15	206 mm	omits D♭	subset
Guide tones, ♭3 and ♭♭7	B♭3 F♭4	6	83 mm	omits G and D♭	subset
Rootless close	B♭3 D♭4 F♭4	6	83 mm	omits G	subset

Spans are measured centre to centre at a 165 mm octave (standard keyboard geometry).

Position	Bass note	Notes in order	Figured bass	Semitones	Span
Root position	G	G3, B♭3, D♭4, F♭4	7	9	124 mm
First inversion: Gdim7/B♭	B♭	B♭3, D♭4, F♭4, G4	6/5	9	124 mm
Second inversion: Gdim7/D♭	D♭	D♭4, F♭4, G4, B♭4	4/3	9	124 mm
Third inversion: Gdim7/F♭	F♭	F♭4, G4, B♭4, D♭5	4/2	9	124 mm

One position per chord tone in the bass. Spans are for close position: voiced inversions appear under Voicings.

Change one note

Chords a single note away, and what moving that note does.

Chord	Change	Formula	Common tones
Gdim	drops F♭	1 ♭3 ♭5	3
Gm7♭5	F♭ becomes F	1 ♭3 ♭5 ♭7	3
Gm6	D♭ becomes D	1 ♭3 5 6	3
Gm	D♭, F♭ becomes D	1 ♭3 5	2
Gm7	D♭, F♭ becomes D, F	1 ♭3 5 ♭7	2
GmMaj7	D♭, F♭ becomes D, F♯	1 ♭3 5 7	2
G6	B♭, D♭ becomes B, D	1 3 5 6	2

Frequencies

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

Reference pitch A440, 12-TET, close root position.

Set theory: prime form, Forte number, interval vector

Absolute pitch class set: {7, 10, 1, 4}
Normal order: [1, 4, 7, 10]
Prime form: (0369)
Forte number: 4-28
Interval vector: <004002>

Pair	Interval	Semitones	Interval class
G to B♭	Minor third	3	3
G to D♭	Tritone	6	6
G to F♭	Major sixth	9	3
B♭ to D♭	Minor third	3	3
B♭ to F♭	Tritone	6	6
D♭ to F♭	Minor third	3	3

Where these facts come from

Every value on this page is derived from the note formula for a diminished 7th applied to the root G, using standard music theory. Nothing here is hand-entered per chord, so the notes, intervals, inversions and frequencies cannot drift out of agreement with each other. Pitches assume 12-TET at A440.

G Diminished 7th

Fingerings

G Diminished 7th: notes and degrees