RONDO

in music, instrumental form characterized by the initial statement and periodic restatement of a particular melody (or section), the various appearances of which are separated by contrasting material. Although any piece built upon this basic plan of alternation or digression and return may be legitimately designated as a rondo, most rondos conform to one of two basic schemes: the five-part (abaca) and the seven-part (abacaba). The latter is symmetrically balanced, since two basically ternary (three-part) aba sections are separated by an often extended, if not always developmental, contrasting c section. The recurrent refrain is sometimes called a ritornello (q.v.). The rondo was an extremely popular form during the last half of the 18th and the early 19th centuries, when it frequently formed the final movements of sonatas, symphonies (Haydn), chamber works, and especially concerti (Mozart). During the same period, the rondo also enjoyed a certain vogue as a separate composition, a well-known example being Beethoven's Rondo a capriccio (also known as Rage Over a Lost Penny), Opus 129. The classical rondo seems to have developed from the French late 17th- and early 18th-century keyboard 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: abacad, etc. Cultivators of the French rondeau include Franois Couperin, Louis Clrambault, and Jean-Philippe Rameau.