G# Diminished (G#dim)
Also written as Ab Diminished (Ab and G# are the same key).
1+b3+b5
Notes in G# Diminished
G# (root)BD
Inversions
Same notes as G# Diminished, with a different chord tone as the lowest note. Useful for smoother movement between chords instead of jumping around the keyboard.
Root position
G# in the bass
1st inversion
B in the bass (G#dim/B)
2nd inversion
D in the bass (G#dim/D)
G# Diminished consists of G#, B and D, played at the same time.
Stack two minor thirds and the fifth shrinks along with the third, producing a triad that never feels at rest. Diminished chords are unstable by design, built to lean somewhere else, usually resolving up by a half step. Played alone it can sound almost comical, but tucked between two other chords it's one of the most useful tension devices in tonal music.