An HBO movie, based on an autobiographical one-man show play. There are at least a dozen high-powered black actors in this, plus Jimmy Smits, all with small parts, all obviously eager to get a chance at a cameo in this sweet little film. But it is dominated, as it must and should be, by S. Epatha Merkerson, from “Law & Order.” She plays a saintly but no-nonsense woman who runs a boarding house for society’s losers. The story is episodic and has no dramatic arc, but hey, it’s real life. Does your life have an arc? Everyone involved is very good. And the film would be worth seeing just for the music. Would you believe Mos Def wailing out on “Caledonia!”? Some hip-hop dudes are good right across the musical spectrum. In fact, during the two big party scenes here … you see why music and dancing were the most valuable resources of black people while they suffered from institutional racism and ostracism from the larger society. Hell, they didn’t need whitey’s approval to be happy. They made “our own paradise on Earth,” and you really want to join in.