| a musical form in three sections, with the third usually an exact repetition of the first. |
ternary form
in music, a form consisting of three sections, the third section normally either a literal or a varied repeat of the first. The symmetrical construction of this scheme (aba) provides one of the familiar shapes in Western music; ternary form can be found in music from the Middle Ages (as in the common arrangement antiphon-verse-antiphon in Gregorian chant) to the present day.
Learn more about ternary form with a free trial on Britannica.com.