Whether it's blasted from boom boxes by righteous urban teenagers or denounced by scolding pundits, rap music these days inevitably comes off as serious stuff. What's been lost amid the media clamor and the hostile braggadocio of the music itself is the fact that rap, for all its incendiary trappings, remains a form of showbiz, as subject to the blind vanities of its stars as any other pop music.
That, as it turns out, is the rudely amusing joke of Rusty Cundieff's Fear of a Black Hat, a low-budget rap-world satire lovingly modeled on the mock-documentary format of This Is Spinal Tap. The movie traces a year in the life of N.W.H. (Niggaz With Hats), a notorious trio of gangsta rappers whose members leader Ice Cold (played by writer-directer Cundieff), ''sergeant at arms'' Tasty-Taste (Larry B. Scott), and DJ Tone-Def (Mark Christopher Lawrence) sport outlandish Dr. Suess-style headgear, in what they claim is a rebuke to the days when bareheaded slaves would get dazed by the sun. A takeoff on N.W.A and Public Enemy, with elements of the randy, butt-worshiping 2 Live Crew thrown in, N.W.H. become platinum hit makers with their No. 1 single, ''Guerrillas in the Midst.'' We see them mouthing off for interviewers, bumping off their various managers (they've had as many as Spinal Tap had drummers), and strutting through such rabble-rousing videos as ''F--- the Security Guards'' and the decidedly less political ''Booty Juice.''
The extremity of rap culture makes it almost too easy to caricature. Cundieff, though, catches something that eluded the makers of last year's clueless CB4. In Fear of a Black Hat, he lampoons rap's raging, nihilistic core not by turning his rappers into cartoon fools but by revealing how N.W.H. use racial politics and their own street credibility to justify their every badass whim (i.e., sex, guns, dissing anyone who isn't them). In a hilarious scene, Ice Cold explains the title of his about-to-be-published manifesto: It's called F.Y.M., which stands for ''F--- Y'All Motherf---ers.'' Like Spinal Tap, who beneath their fog-brained posturing truly believed they were rock gods, N.W.H. are most interested in parading their solipsistic adolescent egos. Fear of a Black Hat never achieves the dizzying cinema verite swirl that made Spinal Tap such a timeless satire. Many of the jokes are too literal (a goof on Vanilla Ice named Vanilla Sherbet). Still, Cundieff has what nearly every commentator on the rap scene has lacked: a first-class bull detector.