D# Diminished (D#dim)
Also written as Eb Diminished (Eb and D# are the same key).
1+b3+b5
Notes in D# Diminished
D# (root)F#A
Inversions
Same notes as D# Diminished, with a different chord tone as the lowest note. Useful for smoother movement between chords instead of jumping around the keyboard.
Root position
D# in the bass
1st inversion
F# in the bass (D#dim/F#)
2nd inversion
A in the bass (D#dim/A)
D# Diminished consists of D#, F# and A, 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.