Nobody else mentioned the Steve Miller Band or Sly and the Family Stone. Buffy Ste. Marie (already mentioned) was fantastic.
The whole thing went south when the shooting started. We'd heard about the bikers charging people money to get water from the Army-style potable water truck, which was supposed to be free, and there were rumors about bikers raping women, but no one knew for sure. Suddenly there was shouting and running, and then pop-pop-popping. I knew it was gunfire but was very high and completely unarmed, so I didn't want to go near it. A much braver friend of mine heard from people running away what was happening and ran toward the commotion. He told me later that he was part of an enraged group who ran the bikers out. He threw rocks at bikers who had guns.
I went to the stage to try to find out what was happening. A Jimi Hendrix lookalike wearing some sort of US flag costume was on stage trying to whip up the crowd into doing something, but people just milled around. I don't think he got the message across that there was violence going on to people who didn't already know.
I decided to go back to the tent where my girlfriend was when I saw a wounded man walking toward me. He'd been shot in the upper right chest just below the shoulder and was bleeding, but not heavily. From the look on his face, he was in shock. He had no idea where he was or where he was going. I wish I'd done something for him.