Musical form characterized by the initial statement and periodic restatement of a melody alternately with contrasting material.
It originated in the French Baroque harpsichord rondeau , where a refrain of 8 or 16 measures is played in alternation with a succession of couplets (episodes) so as to form a chainlike structure of variable length. Most rondos fall into either a five-part ( abaca ) or a seven-part ( abacaba ) form. The rondo was very popular in the late 18th and the early 19th centuries, frequently providing the form for the final movements of sonatas, quartets, symphonies, and concertos.