Minimal is short for minimal techno but also for Minimalist music. This genre can be considered originally American and consists of experimental or Downtown music named in the 1960s based mostly in consonant harmony, steady pulse (if not immobile drones), stasis and slow transformation, and often reiteration of musical phrases or smaller units such as figures, motifs, and cells. Starting in the early 1960s as a scruffy underground scene in San Francisco alternative spaces and New York lofts, minimalism spread to become the most popular experimental music style of the late 20th century. The movement originally involved dozens of composers, although only four—Terry Riley, Steve Reich, Philip Glass, and, less visibly if more seminally, La Monte Young—emerged to become publicly associated with it in America. In Europe, its chief exponents were Louis Andriessen, Karel Goeyvaerts, Michael Nyman, Gavin Bryars, Steve Martland, Henryk Górecki, Arvo Pärt, and John Tavener. The term "minimalist music" was derived around 1970 by Michael Nyman from the concept of minimalism, which was earlier applied to the visual arts. For some of the music, especially that which transforms itself according to strict rules, the term "process music" has also been used. .