Executive producer Martin Scorsese plays host as a virtual firmament of blues stars take over Radio City Music Hall for a night of lovingly played standards and shared memories. For all the talk of the form's indomitable spirit, the picture that emerges is of a cultural artifact in desperate need of preservation as signified by the presence of recovering stroke victim Ruth Brown and lung-removal survivor Hubert Sumlin. Director Antoine Fuqua assembles the concert footage, backstage interviews and archival material into a retrospective of the black experience in America (both musical and otherwise), and he only occasionally makes the mistake of letting the pithy commentary intrude on the sizzling performances. Two of the best nonmusical moments are Vernon Reid's reminder that blues pioneers were not always the nicest of people, and Solomon Burke's bizarre recollection of an especially uncomfortable gig: playing a KKK rally.