Chapter 12

The Leading-tone Seventh Chord

vii°7

• Very closely related to the V7 chord because both chords have three tones in common

• Built on the seventh scale degree of the major, harmonic minor, and ascending melodic minor scales

vii°7

• In major keys, the quality is half-diminished (dm)

• In minor keys, the quality is fully diminished (dd)

Progression of the vii°7

• Can be substituted for the V7 to add variety

• Usually resolve to the tonic, or to the tonic through the V7

Resolution of the vii°7

• The fully diminished seventh chord contains two diminished fifths, which are best to resolve inward. If resolved correctly, the result will be a doubled third factor in the tonic chord, but you can also use normal doubling.

• The root of the vii°7 will resolve upward to the tonic, and the seventh factor will resolve down by a step

Pitfalls to avoid

• Avoid parallel fifths between the third and seventh factors in the half-diminished seventh chord

• Double the third factor of the tonic triad to avoid these parallels.

• Parallel unequal fifths are permitted

Summary

• Resolve the seventh factor of the vii°7 down one diatonic scale degree to the fifth factor of the tonic triad

• Resolve the root upward to the tonic

• The other two voices resolve to the third factor of the tonic triad