Directedby:Robert Altman Starring: Garrison Keillor, Meryl Streep, Lily Tomlin, Kevin Kline, John C. Reilly, Woody Harrelson, Lindsay Lohan, Virginia Madsen, Tommy Lee Jones Rated: PG-13 (for mildly risqu humor) Rnningtime:105 minutes Bestsitedfor: "Home Com- panion" listeners, Altman and Streep fans Least sited for: those ex- pecting something relevant to occur

Watching a Robert Altman film is roughly akin to being a fly on a page of American lore. In films like "Nashville" (Southern politics), "M*A*S*H" (an Army surgical tent), "The Player" (the Hollywood elite) or "A Prairie Home Companion" (backstage at a Midwest radio variety show), one merely has to watch and listen to actually be there. Between Altman's extraordinary ear for dialogue and eye for capturing expression and character nuance, his fans don't have to work hard to enjoy themselves.

In so many ways, "A Prairie Home Companion" is a typical Altman film-and not nearly as cynical as some of his more recent efforts. Oh, the cynicism is there, of course, but it's buried under a heap of fun. There's a sense of chaotic calm at play, a clutter of folks caught inside the muddle of their own heads, all trying to converse at once, blissfully unaware that nobody is really listening.

Here Altman's invasive cinematic style crashes headlong into Garrison Keillor's homespun charm and wry wit; on the surface, it's very much like having a backstage pass to an actual Keillor broadcast. But this isn't about radio-hey, a bunch of folks playing banjo, singing gospel and jawboning about Midwest minutia needs a little cinematic twist. Altman is hardly filming a documentary, after all.

Unfortunately, that twist is "Companion's" curious disappointment. Because for the film's first half, watching a bunch of folks jawboning works just fine, is, in fact, spellbinding. Even if one's musical taste is more LL Cool J than traditional folk and gospel, we quickly forget that we're watching people in song. We're watching the people who sing those songs. And that's "Companion's" greatest strength.

Yet Keillor, who wrote the screenplay, must have decided to delve into filmdom with both feet. (One can only imagine his perusing a "how to" book on screenwriting, suddenly realizing he needed more tension, more action, a boffo ending, a higher power at play.)

What Keillor didn't understand was this-he had me at hello. Rich character study, sterling dialogue and a passing flurry of eccentric personalities would have more than sufficed. For a good 15 minutes we hear backstage banter between Meryl Streep and Lily Tomlin, as Yolanda and Rhonda, the pasttheir-prime Johnson sisters, reminiscing about Mama and all their dead singing relatives.

They break into heartfelt verse now and then while Yolanda's daughter, Lola (Lindsay Lohan), rolls her eyes and scribbles poems about suicide. These moments are priceless, and an entire film of these peculiar character ruminations wouldn't have bored me in the least.

But Keillor can't leave well enough alone. Enter an angel from heaven (Virginia Madsen), who meanders backstage during the broadcast, as if in search of prey. Some folks see her, some can't, but we quickly realize that somebody on stage is about to strum their last chord. Maybe it's a Bible Belt thing-having too much fun has its risks.

The cast, of course, is wonderful. An oddly misplaced Kevin Kline, with the persona of a '30s New York gumshoe, opens the film and actually blends into the scenery (his name is Guy Noir, lest anyone miss the innuendo). Keillor himself comes across as a wry, intellectual bloodhound of a man-yet he's surprisingly void of compassion or emotion.

John C. Reilly and Woody Harrelson play Lefty and Dusty, mischievously hilarious singing cowhands. Tomlin drips sage sarcasm and Tommy Lee Jones is sadly wasted as a corporate henchman who's come to shut down the radio show after the evening's performance. And there's Streep of course, who sucks you in like a full-throttled Hoover. (If you relished her exhilarating last scene in "Postcards From the Edge," you'll thoroughly enjoy her performance in "Companion.") And to hear her speak Minnesotan is a hoot.

In a nutshell: This sometimes hokey, often humorous fictitious rendition of Garrison Keillor's "A Prairie Home Companion" works more than it doesn't-but the unnecessary out-of-nowhere twists spoil some of the fun. If you're a Keillor or Altman fan, by all means enjoy the show. If you've recently flown in from Minnesota, it's a taste of home (although now I know why you left).