G#dim7 Chord on Guitar
G#dim7 = G# – B – D – F (Root, Minor 3rd, Tritone, Major 6th)
G#dim7 stacks a fourth note onto the G#dim triad, completing a chain of four equal minor-third intervals and rounding out the set of only three genuinely distinct diminished-seventh chords available anywhere on the guitar — F#dim7 and Gdim7 are the other two, and every other dim7 shape on the neck duplicates one of these three.
G#-B-D-F: four notes, each a minor third above the last, looping back to G# an octave higher after four such steps. Because the pattern repeats every three semitones, G#dim7 shares its exact pitch collection with Bdim7, Ddim7, and Fdim7 — the same four notes simply renamed depending on which is treated as the root. That symmetry makes dim7 chords a guitarist's most flexible chromatic device, sliding between chords a step apart or pivoting into distantly related keys via reinterpretation.
Fingerings
Barre (4th fret)
How to Practice It
Once the shape is comfortable, slide it up three frets at a time and notice the pitches don't actually change — a hands-on demonstration of the symmetry that no explanation alone conveys as clearly. Use G#dim7 specifically as a passing chord between two diatonic chords a step apart, since that connective role is where it earns its place far more often than as a chord resolved in isolation.
Common Progressions
- A – G#dim7 – A/C# (I sliding chromatically through a passing dim7 to a first-inversion I)
- Am7 – G#dim7 – Gmaj7 (a jazz chromatic descent using the symmetrical chord as connective tissue)
- E7 – G#dim7 – A (V7 substituting into a diminished passing chord before resolving to I)
- G#dim7 – A – F#m – D (a leading-tone resolution opening a longer progression in A major)
FAQ
- Why does G#dim7 share notes with chords on other roots?
- A dim7 chord is built entirely from stacked minor thirds, and three semitones divides evenly into the twelve semitones of an octave four times, so the exact pitch set repeats every three frets — meaning G#dim7 is identical in pitch content to Bdim7, Ddim7, and Fdim7.
- Is G#dim7 the last of the three unique diminished-seventh shapes on guitar?
- Yes — together with F#dim7 and Gdim7, these three shapes cover every possible dim7 chord on the instrument, since any other root duplicates one of these three pitch sets.
- How is G#dim7 actually used in music?
- Almost always as a chromatic passing or connecting chord — sliding between two diatonic chords, briefly substituting for a dominant seventh, or bridging a modulation — rather than as a chord a progression settles on.
- Is G#dim7 hard to play at the fourth fret?
- It's a compact barre with a fairly small stretch, so it's not physically demanding; the harder part is knowing where and why to use it given how flexible its symmetry makes its possible functions.
- Can G#dim7 be reinterpreted as a chord on a completely different root?
- Yes — because of its symmetry, the same four notes can be understood and resolved as Bdim7, Ddim7, or Fdim7 depending on context, and jazz players use that flexibility to justify unexpected harmonic turns.
G#dim7 on other instruments: G#dim7 on Piano. Related: how chords are built, chord finder.