Rhythm notation

Worldwide there are many different approaches to passing on rhythmic phrases and patterns, as they exist in traditional music, from generation to generation.
African music

In the Griot tradition of Africa everything related to music has been passed on orally. Babatunde Olatunji (1927–2003), a Nigerian drummer who lived and worked in the United States, developed a simple series of spoken sounds for teaching the rhythms of the hand drum. He used six vocal sounds: Goon Doon Go Do Pa Ta. There are three basic sounds on the drum, but each can be played with either the left or the right hand. This simple system is now used worldwide, particularly by Djembe players.

Indian music

Indian music has also been passed on orally. Tabla players would learn to speak complex rhythm patterns and phrases before attempting to play them. Sheila Chandra, an English pop singer of Indian descent, made performances based on her singing these patterns. In Indian Classical music, the Tala of a composition is the rhythmic pattern over which the whole piece is structured.

Western music

In the 20th century, composers like Igor Stravinsky, Béla Bartók, Philip Glass, and Steve Reich wrote more rhythmically complex music using odd meters, and techniques such asphasing 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 rhythms 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 (Sandow 2004, 257). LaMonte Young also wrote music in which the sense of a regular beat is absent because the music consists only of long sustained tones (drones). In the 1930s, Henry Cowell wrote music involving multiple simultaneous periodic rhythms and collaborated with Léon Thérémin to invent the Rhythmicon, the first electronic rhythm machine, in order to perform them. Similarly, Conlon Nancarrow wrote for the player piano.