VII7

vii7 is a Roman‑numeral symbol used in tonal music analysis to designate a seventh chord built on the leading‑tone (the seventh scale degree) of a key. In a major key the chord is a fully diminished seventh, consisting of a root, minor third, diminished fifth, and diminished seventh (for example, in C major, vii7 is B–D♭–F♭–A♭). In a natural minor key the chord on the leading tone is also a fully diminished seventh, while in harmonic or melodic minor the same notation is often understood to indicate a half‑diminished seventh (viiø7) unless the context calls for a fully diminished form.

The primary function of a vii7 chord is dominant‑type, creating strong tension that resolves to the tonic triad (I) because the chord contains the leading tone, which has a strong pull upward by a semitone to the tonic pitch. The chord’s three‑voice leading‑tone tendency—root to tonic, third to third of the tonic, and fifth to fifth—produces voice‑leading that drives the progression forward. In classical harmony the vii7 is typically found in first‑species counterpoint and in cadential formulas, while in jazz and popular music it may be used as a chromatic passing chord or to enrich dominant harmony.

Inverted forms of vii7 are labeled vii6⁵, vii4₃, vii4₂, and vii4₁₅, indicating the bass note’s position relative to the chord’s root. These inversions are employed to smooth voice leading or to place the chord in convenient registral positions. Though rare as a tonic substitute, a vii7 can function as a secondary leading‑tone chord, e.g., vii⁷/V, where it resolves to the dominant of the key.