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 Gb Diminished 7th chord?
The Gb Diminished 7th chord (Gbdim7) contains four notes: Gb (root), Bbb (minor third, enharmonically A), Dbb (diminished fifth, enharmonically C), and Fbb (diminished seventh, enharmonically Eb). All four notes are spaced exactly 3 semitones apart.
How does Gb Diminished 7th differ from Gb Diminished?
Gb Diminished is a three-note triad (Gb, Bbb, Dbb). Gb Diminished 7th adds Fbb/Eb as the diminished seventh, completing the symmetrical structure.
Why is the Diminished 7th chord symmetrical?
Gbdim7 contains the same pitches as Cdim7, Ebdim7, and Adim7 — all inversions of the same four notes (C, Eb, Gb, A). Only three unique dim7 chords exist.
How is Gb Diminished 7th used in music?
Gbdim7 functions as the vii°7 of G, resolving up by half step to G Major or G minor. Its enharmonic equivalent F#dim7 is more commonly written in sharp-key contexts.
What songs use Diminished 7th chords?
Diminished 7th chords appear in Michelle (Beatles), throughout Chopin and Beethoven, and in jazz standards for chromatic voice leading. Film scores use dim7 for suspense and dramatic tension.
How many unique Diminished 7th chords exist?
Only three. Gbdim7 shares its notes with Cdim7, Ebdim7, and Adim7. The other two unique groups are Dbdim7 and Ddim7.