Noun
A perpetual motion machine.
(musicology) Pieces of music, or parts of pieces, characterised by a continuous steady stream of notes, usually at a rapid tempo.
(musicology) Whole pieces, or large parts of pieces, which are to be played repeatedly, often an indefinite number of times.
Source: en.wiktionary.orgperpetuum-mobile
Of all god-gifted dispensers of joy, Johann Strauss is to me the most endearing. I willingly admit to having sometimes conducted the Perpetuum Mobile with far more pleasure than many a four movement symphony. Richard Strauss