Systems music is music with sound continua which evolve gradually, often over very long periods of time.[1] Historically, the American minimalists Steve Reich, La Monte Young and Philip Glass are considered the principal proponents of this compositional approach.[citation needed] Works by this group of composers are often characterized by features such as stasis or repetitiveness.
A number of English experimental composers have also developed systems based music particularly Michael Parsons, Howard Skempton, John White, and Michael Nyman.[2]
In the realm of computer music, "systems music" refers to fractal-based, computer-assisted composition, and in particular iterated function systems music, in which a function "is applied repeatedly, each time taking as argument its value at the previous application",[3]