Text: A sound which is stable and which does not have the urgency to resolve is called a consonance. This term refers to chords as well as to intervals. The consonant intervals are: all perfect intervals (except the perfect fourth in certain instances) and the major and minor thirds and sixths. They are divided into two groups, the perfect and imperfect consonances, their placement being determined by their degree of stability. The perfect consonances are the perfect unisons, octaves, fifths, and fourths (the fourth is considered a perfect consonance only when there is a third or perfect fifth below it). The imperfect consonances are the major and minor thirds and sixths.

See Also: CONCORD; ACCORD; SYMPATHY; HARMONY

Source: 13