The Summer's Most Important Movie

''Black folks are definitely 'in,''' says journalist Nelson George, cowriter and associate producer of Strictly Business, a Warner Bros. release due this November that focuses on an uptight, Ivy League black executive who learns to balance racial identity and economic success through his friendship with a homeboy mailroom clerk at his firm. ''And when the year is totaled up, we'll have at least three films (New Jack City, Jungle Fever, and Boyz N the Hood) making over $30 million. And that will confirm the market. The budgets are getting bigger, and the ambition levels are getting bigger.''

But how big can black budgets and ambitions get before they hit the wall of Hollywood cost-consciousness? Spike Lee has had to fight publicly to get a $25-million budget for his biopic about Malcolm X, and commercial flops like Charles Burnett's To Sleep With Anger are just the kind of critically appreciated disappointments that can cause a production head to start thinking about the next cycle of buddy films. If Singleton's second movie — or Matty Rich's, or Mario Van Peebles' — nosedives at the box office, the renaissance could rapidly be over. As a Columbia Pictures executive says, ''You'll see a lot of small-budget black pictures. Then somebody's going to make a big-budget one, and somebody will take a bath.''

Blacks in the film industry have a less cynical set of fears. ''The only thing I'm worried about,'' says George, ''is that we're so concerned about being part of the mainstream that we're losing the edge that brought us there. Being in the Hollywood system will suck everyone dry.''

That note of caution seems about right, given what happened to an earlier group of pioneers: the black directors of the late '60s and early '70s. Despite similar pronouncements at the time, the tough, hard truths of Gordon Parks' Shaft and Melvin Van Peebles' Sweet Sweetback's Baadasssss Song dead-ended in the formula blaxploitation of Fred Williamson action flicks such as Black Caesar and Hell Up in Harlem.

With his first film Singleton has done something amazing — reminded all of us that a ghetto is also a home. But if he's smart (and he is) he's aware that the bottom line always means more in Hollywood than doing the right thing. What gives Boyz N the Hood its true and lasting importance is that it represents a rare confluence of conscience and profit. The message, for once, is the message everyone wants to hear.