Ternary form

A form most commonly used in short pieces consisting of three sections: first section is self-contained and closes in the tonic; second section is in a new key, modulatory and in a contrasting character; the first section is then repeated. Each section begins and ends in the same key. The overall structure of the penultimate movement of a symphony or string quartet (minuet/scherzo - trio - minuet/scherzo) fits in ternary form although each section is usually in binary form. Also used in the slow movements of sonatas (Beethoven's piano sonata Op. 7; Op.10/3). In vocal music, it is widely used in from French chansons to (middle-to-late Baroque) opera arias (da capo aria).