#iio roman degree
A chromatic passing diminished chord — a bridge between ii and iii, raising an inner voice by a half step to link two diatonic degrees with no functional weight of its own.
Where it lives
3semitones from the tonic
Major mode
diminished
Hear it in context: ii-#iio-iii-vi
Piano sound loads on first tap. Resolved in the key of C — every chord links to its full analysis.