What notes are in a G diminished chord?

G diminished contains three notes: G (the root), B♭ (the minor third), and D♭ (the diminished fifth).

What key uses G diminished?

G° is the vii° of A♭ major and the ii° of F minor. Both keys share a four-flat signature.

How is G diminished different from G minor?

Only the fifth changes. G minor is G–B♭–D; G° lowers the D to D♭. The tritone D♭–G generates the chord's instability.

Where is G diminished used in classical music?

Bach's F-minor and A♭-major works rely on G° as a primary cadential preparation. Mozart's K. 397 Fantasia in D minor uses parallel diminished motion; the same logic applies in G°.

G diminished chord — notes, intervals, and practice

G diminished — G, B♭, D♭ — is the ii° of F minor and the vii° of A♭ major. It's a flat-side diminished triad with two flats stacked on a natural root. The chord's tritone (G to D♭) drives strong cadential motion in both parent keys.

Intervals

The G diminished chord stacks two thirds on the root. Each interval and its size in semitones:

G→Bbminor 3rd3 semitones
Bb→Dbminor 3rd3 semitones
G→Dbdiminished 5th6 semitones

On the keyboard

Each note of the G diminished chord highlighted on a piano. Pitch class is what matters — any octave works.

On the guitar

One voicing of the G diminished chord on a six-string guitar fretboard.

Common mistakes

G° contains B♭ and D♭ — both flats are essential. The most common error is reading either as natural; B natural makes a G major chord, and D natural makes a G minor chord. The four-flat signature of A♭ major (or F minor) makes this chord visually compact in score, but on lead sheets without a key signature both flats need explicit accidentals.

In context

G° → C7 → F minor (ii° → V → i) is the standard cadence in F minor. G° → A♭ (vii° → I) caps cadences in A♭ major. In jazz, G°7 substitutes for C7♭9 in F-minor cadences — an expanded version of the same harmonic logic.

Drill it

The G diminished chord is one of 48 in the Chord Trainer. Open the full trainer to practice it alongside related chords with timing and best-time tracking.

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Frequently asked

What notes are in a G diminished chord?: G diminished contains three notes: G (the root), B♭ (the minor third), and D♭ (the diminished fifth).
What key uses G diminished?: G° is the vii° of A♭ major and the ii° of F minor. Both keys share a four-flat signature.
How is G diminished different from G minor?: Only the fifth changes. G minor is G–B♭–D; G° lowers the D to D♭. The tritone D♭–G generates the chord's instability.
Where is G diminished used in classical music?: Bach's F-minor and A♭-major works rely on G° as a primary cadential preparation. Mozart's K. 397 Fantasia in D minor uses parallel diminished motion; the same logic applies in G°.