viio roman degree
The leading-tone diminished chord — pure instability with dominant function. It holds the leading tone and 'wants' to resolve to I almost as strongly as V.
Where it lives
11semitones from the tonic
Major mode
diminished
11semitones from the tonic
Minor mode
diminished
Hear it in context: i-viio-bVII-bVI
Piano sound loads on first tap. Resolved in the key of C — every chord links to its full analysis.