Variations on an Original Theme,Op.15 Variations On An Original Theme, Op.15 Variations on an original theme Variations on an Original Theme, Enigma; Variations on an Original Theme Variations on an original theme, op. 36 'Enigma' Variations on an original theme ("enigma"), op.36 Variations on an original theme,Op.36"Enigma" Variations on a Russian theme, op. 23 Variations on an original theme ("Enigma") op.36