Rap City Rhapsody is a useful primer on rap music for anyone who thinks this pop genre began with the 2 Live Crew and M.C. Hammer. Producer Akili Buchanan offers the viewer a history of rap as well as an analysis of it, drawing on sharp-witted interviews with the novelist Ishmael Reed and San Francisco disc jockey and critic David ''Davy D'' Cook.
Seasoned rap fans may find it funny that Buchanan has decided to offer subtitles for all of the rap music excerpts presented here. But it's also realistic let's face it, your average PBS fan is not likely to be down with the latest street lingo; subtitling will draw many viewers into the music and neatly precludes the eternal pop-music complaint, ''You can't understand the words!'' On the other hand, the printed, on-screen definitions of rap slang did seem a bit much. ''Dissing=Debasing'': okay. But ''Bragging =Braggadocio''?
Rap City Rhapsody was produced by San Francisco public television station KQED, resulting in a pronounced West Coast skew to the rappers profiled. And from Rhapsody, you'd never know that it took Los Angeles and Oakland nearly a decade to produce rap scenes as vital and distinctive as the ones going strong throughout New York City in the late '70s. This quibble aside, Rap City Rhapsody is the sort of enlightened presentation that can't help but widen the music's audience. B+