About the G#dim chord
To play G# diminished, use the first shape above. Place your index finger on the 1st fret of the G string, your middle finger on the 2nd fret of the C string, your ring finger on the 2nd fret of the A string, and your pinky finger on the 4th fret of the E string. Strum all four strings and check that each one rings cleanly.
Root
G#
Quality
Diminished
Notes
G# · B · D
How the G#dim chord works
G#
Root(1)
The home note. It gives the chord its name.
B
Minor third(♭3)
The defining minor interval above the root.
D
Diminished fifth(♭5)
A lowered fifth that adds harmonic tension.