Foreshadowing rock & roll in shameless excess, Al Jolson belted out showstoppers in nearly 20 movies, most of which are unknown to today’s viewers — largely because Jolie’s politically incorrect blackface has kept his movies off TV and video. Compromising eight Jolson films (all of which are new to video except The Jazz Singer), The Al Jolson Collection offers a rare look at — and beyond — Jolson as blackface cliché. Throughout all of these films, the corny sentimentality of the period is offset by the magnetic energy of Jolson’s singing and comic repartee, evident even in the rarely seen Big Boy (1930), which is the most blatantly objectionable for its racial caricatures. Entirely unredeemable, however, is his tasteless watermelons-and-pickaninnies finale to the otherwise modestly entertaining Wonder Bar (1934). The liveliest of these 11 hours and 40 minutes id Go Into Your Dance (1935), in which he’s suitably cast as an egomaniacal Broadway star tamed by a young dancer (ruby Keeler, then the real-life Mrs. Jolson). He was already a movie has-been by then, but Dance justifies MGM/UA’s decision to reincarnate Jolson with this eclectic, crisply transferred collection.