Gimme Shelter, a documentary that some critics call "the greatest rock film ever made," follows the Rolling Stones on their notorious 1969 U.S. tour when 300,000 members of the Love Generation collided with a few dozen Hells Angels at San Francisco's Altamonte Speedway. The movie screens tonight at 7 at the Rock Hall. Tickets cost $5.50, but it's free for Rock Hall members. (Niesel)