Even if you’ve never seen Don’t Look Back, you know it by heart. The “Subterranean Homesick Blues” opener — nicked by everyone from INXS to Bob Roberts — is the most obvious cultural reference point, but in a larger sense this documentary of Bob Dylan’s 1965 U.K. tour is the permanent blueprint for the public’s image of mid-Sixties rock & roll. The glories and agonies of the road, the exuberance of a quicksilver new talent setting the world on fire, the clueless journalists: Director D.A. Pennebaker’s handheld camera captured it all. In the process, he made Dylan an icon, galvanized a generation and helped transform a singular moment in the evolution of “youth music” into riveting, indelible drama.