Steve Reich
Sorry this is so late guys.
I played excerpts from 4 pieces and they were:
Come Out tape, 1966
Pendulum Music (the cover performed by Sonic Youth, 1999) (original: microphones, amplifiers and loudspeakers, 1968)
Pulses (Music for 18 Musicians). 1974-1976
Tehillim I: Psalms 19.2-5 1980
I got a lot of information from his website stevereich.com and wikipedia. On his website there is information about some of his newer pieces which are very different from the early work I presented.
If anyone wants to hear more of Steve Reich, let me know.