viiø7

viiø7, or the leading-tone half-diminished seventh chord, is a common diatonic seventh chord in tonal music. The symbol uses the slashed circle to indicate a half-diminished quality. This chord is built on the seventh scale degree of the key and serves as a predominant chord that typically moves the harmony toward the tonic or toward the dominant.

Construction and example: A viiø7 consists of a diminished triad plus a minor seventh above the root. Specifically, it contains a root, a minor third, a diminished fifth, and a minor seventh. In C major, the chord on B is B-D-F-A: B-D-F forms a diminished triad, and A is the minor seventh above B.

Function and voice-leading: As a predominant function, viiø7 commonly resolves to I (the tonic) and can also lead to V. The leading-tone note (the root of the chord) tends to move upward to the tonic, while the other voices follow standard contrary- or common-tone voice-leading patterns to establish the resolution.

Notational context: In major keys, the diatonic seventh-chord built on the leading tone is typically written as viiø7. In minor keys, the same degree can produce a fully diminished seventh in some harmonic contexts, which may be notated vii°7 rather than viiø7 depending on the scale and harmonic framework used. The half-diminished symbol thus identifies a specific sonority that is distinct from the fully diminished seventh chord.