Piece of mus. which is a varied version of a well‐known tune or of an orig. theme specially comp. as basis for variations. Some variations follow the orig. tune closely, others make the briefest reference to it, sometimes harmonically rather than thematically. Popular form with composers from 16th cent., as in ‘divisions on a ground'. In some comps., one movement takes the form of a theme with variations, e.g. the finale of Beethoven's Eroica sym., and movements of several Haydn syms. Among famous sets of variations are Beethoven's on a waltz by Diabelli, Brahms's on a theme by Haydn, Schumann's Études symphoniques, Strauss's Don Quixote, Elgar's Enigma, Rachmaninov's Rhapsody on a theme of Paganini, and Britten's Variations on a Theme of Frank Bridge.