Home > Algorithmic composition

Algorithms (or, at the very least, formal sets of rules) have been used to compose music for centuries; the procedures used to plot voice-leading in Western counterpoint, for example, can often be reduced to algorithmic determinacy. The term is usually reserved, however, for the use of formal procedures to make music without human intervention, either through the introduction of chance procedures or the use of computers. A (largely academic) distinction is sometimes made between composers who use indeterminate (e.g. stochastic) procedures to compose music and those who use routines which produce deterministic results given a fixed input into the algorithm.

Many algorithms that have no immediate musical relevance are used by composers as creative inspiration for their music. Algorithms such as fractals, L-systems, statistical models, and even arbitrary data (e.g. census figures, GIS coordinates, or magnetic field measurements) are fair game for musical interpretation. The success or failure of these procedures as sources of "good" music largely depends on the mapping system employed by the composer to translate the non-musical information into a musical data stream.

Composers known for their use of algorithmic procedures:

• John CageJohn Milton Cage ( September 5, 1912 August 12, 1992) was an experimental music composer and writer, possibly best known (some might say notorious) for his piece 4 33 often described (somewhat erroneously) as "four and a half minutes of silence. He was an
• Iannis XenakisIannis Xenakis ( May 29, 1922 February 4, 2001) was a Greek composer who spent much of his life in Paris, France. He is acclaimed as one of the most important composers of contemporary music. He was born in Braila, Romania, and studied architecture in Ath
• Charles DodgeCharles Dodge (Jun 5, 1942 in Ames, Iowa) is an American composer best known for his electronic music. He is a former student of Darius Milhaud, Gunther Schuller. He co-wrote Computer Music: Synthesis, Composition, and Performance BooksEnthsiast.com. His bes
• Paul LanskyPaul Lansky (born 1944) is one of the 'original' electronic music or computer music composers who has been producing works from the seventies right up to the present day (see discography, below). A former student of George Perle, he is a professor of musi

Algorithmic techniques have also been employed in a number of systems intended for direct musical performance, with many using algorithmic techniques to generate infinitely-variable improvisationImprovisation is the act of making something up as you go along. This term is usually used in the context of music, theater or dance. Music Jazz and Bluegrass are well-known for using improvisation. It features in many kinds of traditional music, includins on a predetermined theme. An early example was LucasArtsLucasArts Entertainment Company (sometimes shortened to LEC), is a video game developer and publisher. The company was famous for its line of point-and-click adventure games and today mainly produces games based on the Star Wars franchise. The company had' 1982Events January January 6 William Bonin is convicted of being the "freeway killer". January 8 AT&T agrees to divest itself of twenty-two subdivisions January 11 Mark Thatcher, son of the British Prime Minister Margaret Thatcher, disappears in the Sahara du computer game Ballblazer, where the computer improvised on a basic jazz theme composed by the game's musical director. A more advanced implementation of this is present in the music subsystem of MicrosoftMicrosoft Corporation , headquartered in Redmond, Washington, USA, is the world's largest software company (with over 50,000 employees in various countries, as of May 2004). Microsoft develops, manufactures, licenses and supports a wide range of software's Xbox games console - the game plays variations on a human composer's theme, but varies its improvisations based on real-time events in the game (so, for example, the music sounds more staccato and dramatic during fight scenes, but is gentler and more mellow afterward).

Similar "generative music" systems have caught the attention of noted composers. Brian Eno has produced a number of works for the Sseyo Koan fractal music system, which produces ambient variations for web-pages, mobile devices, and for standalone performance. The copyright status of these "generative" works is unclear: Sseyo claims to own the copyright of all final Koan performances, although the original "composition" is supplied by the composer and the "performance" is largely the result of the user's computer's own random number generator.