This sort of "artistic documentary" marks a milestone in our culture and it's really a must-see for people interested in history. The DVD version contains important additional features such as excerpts from a long KSAN call-in show the next day. Some of the callers were principals in this event and their commentary is valuable. In addition, there are some incredible still photo collections on the DVD that go even further to capture the climate at this event.
There is a lot of talk about "Hells Angels" this and that in the reviews here. The Hells Angels were not the primary problem - it was a terrible combination of sloppy organization, third parties who reneged on deals and contributed to the problem, and the concert-goers themselves. As some callers to the KSAN show commented, "I was at Woodstock, and Altamont was completely different. Nobody came together. We had no spirit of community. The whole thing was hurried and stayed tense throughout." So imagine 300,000 people working hard to get their groove on quickly - since the concert was only confirmed a day or two prior - using whatever they could roll up in a paper, stir into their cheap wine, or drop on a sugar cube. Then their heroes come up onto the 20'x20'x3'-high stage and viola, you have a massive problem on your hands whether security was Superman, Sgt. Joe Friday and his partner Bill Gannon, Acme Security out of Walla Walla, or the Hells Angels. There was going to be violence. It certainly didn't help that the organizers told the HA to park their bikes right next to the stage. With the crowd as it was, that was guaranteed disaster for a few people.
What a way to end the '60s flower power era.