Music based on composer-defined systems, usually involving repetition. The term, like "ambient music", was probably coined by Brian Eno, but he
actually founded neither genre. It influenced the Eno-midwifed
Frippertronics. Early examples: Terry Riley's In C, where musicians play a sequence of patterns at their own individual paces, making for a shifting texture. Or Steve Reich's tape loops that changed character as they were overlapped or altered. Pop-ified: Autechre.