English director Isaac Julien's history of blaxploitation movies, whose title is a play on Melvin Van Peebles's pioneering 1971 SWEET SWEETBACK'S BAADASSS SONG, may not be the last word on the genre. But as quick and dirty overviews go, it's a blast. Blaxploitation movies burned bright and flamed out fast; born in 1971, they were gasping their last degenerate breaths four years later. But what years they were! Julian knows his history; he understands how van Peebles's searing SWEET SWEETBACK built a bridge between independent exploitation, experimental filmmaking and an increasingly empowered African-American audience clamoring to see movies in which black folks didn...