Who pioneered the concept of "minimalism" in music?

The answer is Steve Reich, who is widely recognized as a foundational figure in the development of minimalism in music. Minimalism is characterized by the use of repetitive patterns, gradually shifting harmonies, and a focus on the fundamental aspects of sound and rhythm. Reich's works often employ phasing techniques, where identical musical phrases are played in slightly different tempos so that they eventually shift out of sync with one another. This creates an evolving, complex texture from what initially appears to be simple material. His compositions, such as "Music for 18 Musicians" and "Drumming," exemplify the minimalist aesthetic and have significantly influenced both contemporary classical music and various other genres.

While other composers like Philip Glass, John Adams, and Terry Riley also contributed to the minimalist movement, Reich's innovations and techniques stand out as particularly pioneering, establishing many of the principles that define minimalism today.