A comical and retrospective memoir of segregation and discrimination in America's golden age of denial, "Liberty Heights" is director Barry Levinson's fourth movie built around his memories of Baltimore in the 1950s and '60s.

Told from the perspective of Ben Kurtzman (Ben Foster), the younger of two brothers living in an almost exclusively Jewish enclave of the city, the foundation for Levinson's story is the brothers' experimentation with the era's cultural polarization.

Ben's school has just been desegregated and he befriends a pretty new black student named Sylvia (Rebekah Johnson), something that doesn't sit well with either kid's folks.

"Oh, just kill me now!" kvetches his aghast mother (the absolutely choice Bebe Neuwirth), instantly awash with what-will-the-neighbors-think hysteria.

A sheltered Sinatra devotee who has never been told his father (Joe Mantegna) makes a living running an illegal numbers game out of a failing burlesque house, Ben gets his first exposure to rock 'n' roll and ribald comedy (Red Foxx) listening to records at Sylvia's house -- until her conservative father (James Pickens, Jr.) comes home early one afternoon to find a white boy hiding in her closet.

Meanwhile, elder Kurtzman brother Van (Adrien Brody, "Summer of Sam") becomes smitten with a flirtatious, WASP-y princess (Carolyn Murphy) when his band of friends intrepidly party-hop in her affluent part of town. Van spends most of the movie on a "Cinderella"-like quest for his dream girl, buttering up gentile pals for information -- not realizing that one of them (Justin Chambers) is her boyfriend, who's just yanking his chain, in part because he's Jewish.

Levinson takes ironic swipes at McCarthyism, the red scare and The Bomb (Ben and Sylvia giggle at the pointlessness of a duck-and-cover drill at school), and creates an vivid, enveloping '50s atmosphere through manners and moods, and with a crisp, bright, astoundingly detailed visual signature. The whole movie looks and feels like a lovingly restored '55 Cadillac. You can almost smell the new upholstery and feel the starch in costumes.

Conversely, the writer-director makes the strange call of giving his age-of-innocence teenagers unrealistically suave and nonchalant attitudes toward everything from racism to promiscuity, premature ejaculation and homosexuality -- as if they're all disciples of MTV's "Loveline" call-in show, which they pick up through some time-warping TV.

Even when the numbers game gets Ben's dad tight spot that results in the boy being kidnapped after sneaking out to a James Brown concert with Sylvia, he's disaffected through the whole episode, barely shrugging when a gun is waved in his face. You know any teenagers that cucumber cool? Neither do I. And this is supposed to be the '50s, no less!

Yet Foster, Johnson, Brody and Murphy (all but Brody are film rookies) somehow seem to remain inherently true '50s teenagers (although their lives don't seem to extend much beyond the plot). None of them lose touch at any point with their witty, smartly-drawn characters, even when called on to deviate from how said characters would likely behave.

Foster has something of a Eisenhower-era Christian Slater vibe going on, making his polite rebelliousness totally charming (and he gives good voice-over). Brody genuinely captures Van's college-age, cusp-of-manhood hesitancy.

Johnson and Murphy make stimulating objects of desire, ever more complex than they seem at first. Especially Murphy, whose porcelain sweater girl is masking a lot of emotional baggage.

"Liberty Heights" has a tendency to lag from time to time, which, coupled with the kids' oddly casual dispositions, impedes on the otherwise infectious nature of Levinson's wonderful, underhanded way of cracking wise.

But in spite of its nagging and bewildering flaws, "Liberty Heights" is movie that inspires broad, lingering smiles, and for Levinson fans it's an astute companion piece to his Baltimore-based "Diner," "Tin Men" and "Avalon."