Perpetuum mobile (Latin), moto perpetuo (Italian), mouvement perpetuel (French), literally meaning "perpetual motion", means two distinct things:

1. Pieces of music, or parts of pieces, characterized by a continuous steady stream of notes, usually at a rapid tempo.

2. Whole pieces, or large parts of pieces, which are to be played repeatedly, often an indefinite number of times.

Even though everything is notated using musical notation, the music is sort of one long loop. The ostinato repeats with developing material above.

This 3rd of seven 'mobiles' features syncopation, use of the Bartok pizzicato, and complex, interlocking woodwind lines.

Instrumentation: Piccolo, 2 Flutes, Oboe, English Horn in F, 2 B-Flat Clarinets, B-Flat Bass Clarinet, 3 Bassoons, Contrabassoon, Snare Drum, Bass Drum, Suspended Cymbal, Violoncello Solo, Violin I, Violin II, Violas, Violoncello I, Violoncello II, Double Basses