 Varèse would not realize these predictions until his tape experiments in the 1950s and 60s.Some of Edgard Varèse's works, particularly "Arcana" make use of the "idée fixe", a fixed theme, repeated certain times in a work.The "idée fixe" was most famously used by Hector Berlioz in his "Symphonie fantastique"; it is generally not transposed, differentiating it from the leitmotiv, used by Richard Wagner.