Editing Rhythm (section)

===Western music===
In the 20th century, composers like [[Igor Stravinsky]], [[Béla Bartók]], [[Philip Glass]], and [[Steve Reich]] wrote more rhythmically complex music using [[List of works in unusual time signatures|odd meters]], and techniques such as [[Phasing (music)|phasing]] and [[additive rhythm]]. At the same time, modernists such as [[Olivier Messiaen]] and his pupils used increased complexity to disrupt the sense of a regular beat, leading eventually to the widespread use of [[irrational rhythm]]s in [[New Complexity]]. This use may be explained by a comment of [[John Cage]]'s where he notes that regular rhythms cause sounds to be heard as a group rather than individually; the irregular rhythms highlight the rapidly changing pitch relationships that would otherwise be subsumed into irrelevant rhythmic groupings.{{sfn|Sandow|2004|p=257}} [[La Monte Young]] also wrote music in which the sense of a regular beat is absent because the music consists only of long sustained tones ([[drone (music)|drones]]). In the 1930s, [[Henry Cowell]] wrote music involving multiple simultaneous periodic rhythms and collaborated with [[Leon Theremin]] to invent the [[rhythmicon]], the first electronic [[Drum machine|rhythm machine]], in order to perform them. Similarly, [[Conlon Nancarrow]] wrote for the [[player piano]].