Gimme Shelter

Much of the film chronicles the behind-the-scenes dealmaking that took place to make the free Altamont concert happen, including much footage of well-known attorney Melvin Belli negotiating by telephone with the management of the Altamont Speedway. The movie also includes a playback of Hells Angels leader Ralph "Sonny" Barger's famous call-in to radio station KSAN-FM's "day after" program about the concert, where he recalls, "They told me if I could sit on the edge of the stage so nobody could climb over me, I could drink beer until the show was over."

The action then turns on the concert itself at the Altamont Speedway, the security for which was provided by the Hells Angels (armed with pool cues). As the day progresses, with drug-taking and drinking by the Angels and members of the audience, the mood turns ugly. Fights break out during performances by The Flying Burrito Brothers and Jefferson Airplane; Grace Slick pleads with the crowd to settle down. At one point Jefferson Airplane lead singer Marty Balin is knocked out by a Hells Angel; Paul Kantner attempts to confront "the people who hit my lead singer" in response. Jerry Garcia and Phil Lesh arrive, but The Grateful Dead opt not to play after learning of the incident with Balin. (Crosby, Stills, Nash, and Young also performed at the concert but are not shown in the movie).
By the time The Stones hit the stage, it is evening, and the crowd is especially restless. The Stones open with "Jumpin' Jack Flash." They are also shown performing "Sympathy for the Devil" as tension continues to build. It is during the next song, "Under My Thumb", that a member of the audience, 18 year old Meredith Hunter, pulls out a revolver in the course of a melee near the stage, and is stabbed to death by Alan Passaro, a member of the Angels.
The late Baird Bryant, one of the many cameramen in the film, caught Meredith Hunter's stabbing on film. The film sequence clearly shows the silhouette of a handgun in Hunter's hand as a member of the Hells Angels enters from the right, grabs and raises the gun hand, turning Hunter around and stabbing him at least twice in the back before pushing Hunter off camera.
Amongst the camera operators for the Altamont concert was a young George Lucas, who went on to become a successful film director in his own right. At the concert his camera jammed after shooting about 100 feet (30 m) of film, and none of his footage was incorporated in the final cut