Imagine The Sound is an incredible documentary - Cecil Taylor, Archie Shepp, Bill Dixon and Paul Bley. I'm only really familiar with Dixon and Taylor, but all give amazing performances, great interviews and it's extraordinarily well done. I got a great quality rip from cinemageddon, it's well worth watching for anyone with even a casual interest in experimental music.
I've also been listening to Frank Wright a lot too - I picked up a copy of Your Prayer on LP recently and hot damn what a record.