Rondo

In rondo form, a recurring theme alternates with a number of contrasting sections called episodes. It can be represented as ABACADA. The number of episodes can vary from piece to piece, and the recurring element is sometimes slightly varied or shortened to avoid monotony.

The form began to be commonly used from the classical music era, though it can be found in earlier works. In the classical and romantic periods it was often used for the last movement of a sonata, symphony, concerto or piece of chamber music.

A common variation on rondo form is to combine it with sonata form, creating a sonata-rondo. Here, the first episode acts in a similar way to the second subject in sonata form by appearing first in a key other than the tonic and later being repeated in the tonic key.