Here is a video trailer for Steve Reich’s ‘Music for 18 musicians’. His process composing is brilliant. There is also a challenge for anyone who wishes to accept. There is a piece of process music playing somewhere on an internet radio station, that is created using synthesized bell noises that are playing in the same style as Reich’s ‘Come Out’ , by starting off playing in time then slowing slipping out of time. However, this piece eventually comes back around to where it started but it has been going on for ages and finishes in a couple of years or so.
So if your up for the challenge….good luck!