Although any kind of aba pattern may be correctly defined as ternary, the term most precisely denotes the form exemplified by the minuet and trio of the Baroque suite and the Classical symphony and sonata, as well as the da capo aria of the Baroque cantata and oratorio and 18th-century opera.

Ternary form is defined as ABA structure. This means the piece starts with the main theme, goes to contrasting material, and then returns with that exact main theme material to end it. Ternary form looks a lot like rounded binary form, however, the key difference is that the last section operates independently of the B section.

It is usually schematized as A–B–A. Prominent examples include the da capo aria "The trumpet shall sound" from Handel 's Messiah, Chopin 's Prelude in D-Flat Major "Raindrop", (Op. 28) and the opening chorus of Bach 's St John Passion.

It is usually schematized as A–B–A. Examples include the de capo aria “The trumpet shall sound” from Handel’s Messiah, Chopin’s Prelude in D-Flat Major (Op. 28) and the opening chorus of Bach’s St John Passion.