Variation is a fundamental musical principle, yet its most naked expression – variation form – resists all but the broadest descriptions. This book offers listener, performer, analyst and composer an eclectic array of approaches to ‘Theme and Variations’, including: patterns of departure and return; real versus perceived time; strategies of propulsion and closure in an intrinsically cyclic and open-ended form; the interplay of authorial voices deriving from dialogue between the ‘self’ of variations and the ‘other’ of their theme; critique of a theme through a set’s generic references; drama and narrative achieved through textural and tonal control; and the intrinsic sound of a variation, so different from that of a freely composed work. These topics are introduced through a general survey of the form, seen through the prisms of the provenance of themes and the ideologies of sets, before being developed through close study of Brahms’s variation sets and movements.