Lisa Cholodenko's Laurel Canyon is a confidently made high comedy in which an uptight young man (Christian Bale) brings his fiancée (Kate Beckinsale) to live with his bohemian record-producer mom (Frances McDormand) in Los Angeles. Sam has rebelled against his unconventional music-biz upbringing--Jane raised him by herself in a hazy, languid, druggy, sexually free atmosphere. He now has a mania for order. He went to medical school, and is launching a career in psychiatry. Alex, his partner, is a biologist completing her dissertation.

Jane drives Sam crazy. It wasn't his intention to share her Laurel Canyon house; she was supposed to have vacated it. But she gave her beach house away to her last lover, and her current squeeze, a young Brit named Ian (played by the golden-haired Alessandro Nivola, a Yankee with an uncanny gift for playing Englishmen), is ensconced in the studio next door with his band, completing a record.

While Sam is beginning his residency, and struggling to tamp down his desire for a gorgeous Israeli co-worker, Sara (Natascha McElhone), Alex works away in her room. Inevitably, the strains of the rock-and-roll, the sweet smell of marijuana and Jane's charisma lure Alex away from her laptop.

Cholodenko is adroit with her terrific cast. But there's something about Laurel Canyon that makes you uneasy, as superficially enjoyable as it is. At first the problem seems to be that the set-up--a repressed eastern blue-blood woman is primed for loosening up, a son tries to hold onto the normal lifestyle that he adopted in defiance of his free-spirit mother--is too conventional, and so is not as funny as it's meant to be.

The deeper problem is that Cho­lodenko's rhythms aren't right for this kind of comedy, or perhaps any kind. Her heart may be with free-wheeling Jane, but in style and tone the movie might have been conceived by Sam: it keeps going serious, and the scenes are shaped to make points.

At the hospital, Sam handles the case of a teenager who's freaked out on ecstasy. The boy's mother is so fixated on how his behavior is an attack on her middle-class standards that Sam has to tell her to shut up and focus on her troubled son. The moment when he silences this self-absorbed prig should be hilarious, but Cholodenko uses it to underscore the irony: this mother-son relationship is the same as Sam and Jane's, only in reverse. You can't make a joke like this work by pointing red arrows at it.

Making the son who's desperate to define his life by something other than his hippie mother into a shrink is a great comic idea. But Cholodenko softens the figure of Jane so much that Sam comes across as the nutty one. A childhood spent with Jane must have been both heavenly and horrible. Cholodenko won't acknowledge the downside to Jane's lifestyle, or that people like her are narcissists who make dreadful parents.

In one scene, Ian persuades Alex to join him and Jane in the pool, where they're bathing nude. Alex strips down to her underwear, joins hands with both of them, and kisses each on the lips. Then Cholodenko fades out on what the viewer takes to be a three-way romp. Later, though, it's implied that nothing happened, and when Ian tries to get Alex in bed with him and Jane, it's Jane who rejects the plan as a betrayal of her son. Here the movie seems both coy and unconvincing. Jane's sensitivity and conscience don't fit her character. Cholodenko clearly doesn't want to deal with the real dangers of growing up with a mother like Jane. She makes her as benign as Auntie Mame.

It's a missed opportunity. McDormand, who is close to being an American Jeanne Moreau here, could have delivered the performance the movie needs. The best reason to see the movie is to admire the skill of the actresses, including Beckinsale, who's so effortlessly deft at playing conventional women that her talent gets overlooked (as it did in Pearl Harbor and The Golden Bowl), and McElhone, who's luscious in the scenes with the beleaguered Sam. Bale is a marvelous actor, but he is stuck with an unplayable part--the consequence of Cholodenko's skewed vision of this mother-son relationship.

This is the kind of movie Paul Mazursky became famous for making (Bob and Carol and Ted and Alice, Down and Out in Beverly Hills), and in his version the temptations of Laurel Canyon would have been more sensuous, the tone more complex, the conflicts funnier. It would also have been more honest.