Grizzled white bluesmen (Elvin Bishop, Barry Goldberg, Nick Gravenites, Harvey Mandel, Charlie Musselwhite, Corky Siegel) recall their youthful encounters with grizzled black bluesmen (Muddy Waters, Howlin’ Wolf, Otis Rush, Junior Wells) amid the south-side clubs of the 1960s. Directed by John Anderson, this documentary follows the usual template for such exercises—talking-head interviews interspersed with live performances from a reunion concert—and paints a rosy picture of the era, stressing the black and white players’ fellowship before the altar of the blues. Left unexamined, for the most part, is the complicated dance in which the more talented white acolytes (Mike Bloomfield, Paul Butterfield) copied their mentors’ licks, catapulted to the top of the music business, and (sometimes) pulled their heroes up after them. With Buddy Guy, Bob Dylan, Keith Richards, and Jack White.