Irregular resolution

In music, an irregular resolution is when one dominant seventh chord resolves irregularly into another.

The following types have been identified:
*Type I, in which the root motion descends by minor third. C, E, G, Bmusic|flat would resolve to Cmusic|sharp, E, G, A; two tones are common, two voices move by half-step in contrary motion.
*Type II, in which the root motion rises by minor third. C, E, G, Bmusic|flat would resolve to Dmusic|flat, Emusic|flat, G, Bmusic|flat; again, two tones are common, two voices move by half-step in contrary motion.
*Type III, in which the root moves a tritone away. C, E, G, Bmusic|flat would resolve to Cmusic|sharp, E, Fmusic|sharp, Bmusic|flat = Amusic|sharp; again, two tones are common (with enharmonic change), two voices move by half-step in contrary motion.

Type I is common from the 18th century; Type II may be found from the second quarter of the 19th century; Type III may be found from the mid-19th century. The composer Richard Edward Wilson is responsible for the categorization.