The G Diminished 7th chord is a four-note chord made up of G, B♭, D♭, and F♭. It is built from a root, minor third, diminished fifth, and diminished seventh.
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 |
G Diminished 7th Inversions
| Position | Notes |
|---|---|
| Root Position | G – B♭ – D♭ – F♭ |
| 1st Inversion | B♭ – D♭ – F♭ – G |
| 2nd Inversion | D♭ – F♭ – G – B♭ |
| 3rd Inversion | 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.
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:
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.