Perpetuum mobile, op. 257

Perpetuum mobile, subtitled Ein musikalischer Scherz, dates from 1861. The joke is structural: the piece is written so that it can circle back on itself indefinitely, and the score offers no ending at all, leaving the conductor to stop it — traditionally by turning to the audience and remarking that it goes on like this forever. Strauss built the music from a single continuous semiquaver motion passed around the orchestra, with the melodic interest carried above it. It is one of the few pieces in his output whose point is a formal conceit rather than a dance function.