Ron Mann's examination of 4 of the pioneers of Free Jazz provides anyone with ears to hear a wonderful opportunity not only to hear some ferociously intelligent music but also to hear, from the mouths of geniuses, part of the history of what is still some of the most aurally challenging sounds to come from North America in the last 50 years. So glad it's available on DVD, despite the fact that the format really isn't suited to analog pictures and sound.