The perfectly admirable adjective mainstream is under fire these days: Turn out enough pap under the guise of giving the people what they want, and the people are eventually going to say, Enough with the Adam Sandler vehicles and Fathers' Day. It's time, though, to reclaim ''mainstream'' as a prized American attribute especially when applied to In & Out, which is that groundbreaking thing, a truly funny, sophisticated, compassionate, mainstream Hollywood comedy about very modern homosexuality. Unqueeney, untortured, American homosexuality. The kind that exists everywhere, not just in the drag-loving Miami of The Birdcage or in the unspoken glances between Batman and his boy wonder.
In the heartland America of director Frank Oz and screenwriter Paul Rudnick, questions of gayness come to pretty, fictional Greenleaf, Ind. Howard Brackett (Kevin Kline) is a popular high school English teacher. To quote the bards of Seinfeld, he's ''single, thin, and neat.'' He's also engaged to Emily (Joan Cusack), whom he has been courting with less than lustful urgency for three years. Howard is due to marry Emily at the end of the week, to the intense pleasure of his wedding-loving mother (wonderful Debbie Reynolds, just 20 degrees less cockeyed than she was in Mother). In the days before the event, however, fate intervenes: While accepting an Academy Award, a Hollywood heartthrob who was once Howard's student (Matt Dillon, generous in self-mockery) pays tribute to his old drama coach. ''And he's gay!'' blurts the Oscar winner to the TV-watching world.
Greenleaf is stunned. Howard is stunned. ''I'm not gay!'' he assures his parents, his fiancee, his students. The media barrel into town (''Should gays be allowed to handle fresh produce?'' one reporter in the pack hollers). And one shark in particular, a slick TV-ratings chaser named Peter Malloy (Tom Selleck), works the story even harder than most. Peter, you see, is gay and out. And he urges Howard to be the same.
(Stop here and skip to the next paragraph if you are in suspense and want to stay that way.) Howard does come out. At the altar. How Greenleaf handles the news pleasurably fills the remaining half of the movie's running time.
(Welcome back.) What we have here is an old-fashioned story about a man who grows through adversity (although the moments of anxiety are suspiciously few). We have a story in which a character is appreciated by his community (although the climactic scene is discordantly schmaltzy). And in Kline defter and more elegantly contained in his comedy than I've ever seen him we've got a leading character who's easy to love.
Garlands of kudos for this casual, confident fantasy on 1997 sexual politics go to Rudnick and Oz. Rudnick's screenplay is as suavely funny as one would expect from the writer of Addams Family Values and Jeffrey surely the only writer I'd trust to use ''Yentl'' as a punchline. But it is Oz's graceful control of comic timing the kind of timing honed on his far more unnerving ''mainstream'' comedies Dirty Rotten Scoundrels and What About Bob? that pulls In & Out way up, onto a new playing field: minority gay sensibility as majority virtue.
The intriguing taste of Oz's subversive sweetness combined with Rudnick's smooth tartness inspires the cast to exceptional performances. Selleck charms by playing in sly contrast to his own forceful, determinedly hetero persona; Cusack projects real neediness while earning major laughs. In smaller roles, the players (including Bob Newhart as a buttoned-down school principal and skinny model Shalom Harlow parodying herself as a skinny model) show they can live it up without camping it up.
And isn't that, after all, the American way? In & Out proves that a comedy about homosexuals doesn't need to be loud to be proud. It just needs to be funny and the mainstream will follow it anywhere. A-