The free concert at the Altamont Speedway in Northern California at December 6th in 1969 was supposed to be a celebration of music, peace and love. The same way that the Woodstock-festival had been less than four months earlier. The Rolling Stones were the headliners, after a day of music filled by Santana, Jefferson Airplane, The Flying Burrito Brothers, Crosby Stills Nash & Young and the Grateful Dead.
The day started of well with everyone in good spirits during the Santana-gig, but soon turned for the worse. Marty Balin, the singer of Jefferson Airplane, got knocked unconscious during their set by one of the Hells Angels present to do the security. It was a rough and rowdy crowd, and the supposed security didn't help the situation either. Grateful Dead decided that there wasn't good enough security in place and didn't perform. The band left the site before the worst things happened.
There was a lot of delays, and the crowd was in a sour mood when the Rolling Stones finally got on stage. They didn't get through more than two songs before they had to stop during 'Sympathy For the Devil' to get the crowd to stop fighting. After some more songs the band stops again during the performance of 'Under My Thumb'. During this stop one member of the audience pulls out a gun, and is then killed by some Hells Angels in self defense. This is clearly seen in the documentary 'Gimme Shelter' from 1970. It's a really eerie scene.
The band doesn't get to know that this person got killed before after the show, and they played on and did a whole concert without any more incidents.
A really bad scene and it's hard to watch those minutes of the documentary. Many have seen this happening as a sort of "death to the sixties", and it's hard to argue with that. A lot of things had changed since the love-ins and the peace and love of a couple of years earlier.