Mamma Mia! (PG-13, 2008)

With her wedding fast approaching, 20-year-old Sophie (Amanda Seyfried) does the unthinkable: She invites three men -- Sam (Pierce Brosnan), Bill (Stellan Skarsgard), and Harry (Colin Firth) -- from her mother Donna's (Meryl Streep) past to the Greek isle-set festivities without telling her. Donna dated all three one long-ago summer, and one of them is Sophie's father, though she's not sure which one. But Sophie's convinced that one of them should walk her down the aisle, even if it means wreaking havoc just before the big day.

Based on the hit Broadway musical of the same name, MAMMA MIA! is a frothy concoction that manages to entertain despite that fact that it's disjointed, nonsensical, and fairly cheesy. Onstage, you can forgive all these shortcomings -- the music, the dancing, and the theatricality of it all sweep you away. But onscreen it's a more hazardous bet. Though some of the musical numbers soar -- "Dancing Queen," of course, and the infectious "Mamma Mia!" -- many more hit the wrong note. Although Streep is formidable (who else can meld camp with believable emotion?) and actually sings quite prettily, the dance numbers might make you laugh in all the wrong places. Seeing Streep in Spandex, her straggly mane tossing about, is a little like witnessing your mom let loose at a party after one too many drinks: Your heart soars at her joie de vivre, but you also kind of want her to stop. Still, Streep's acting chops serve her well; Christine Baranski, who plays Donna's cougar-y sidekick, also fares well, and Julie Walters is just plain fun. Brosnan is dashing as always, though singing isn't his strong suit. And Firth and Skarsgaard seem like afterthoughts.

In the end, it's Seyfried who frankly saves the whole enterprise. Her Sophie beseeches you to check your judgments at the door. Her voice is outstanding, managing to ground the silliness of ABBA's greatest hits. And the island? It's so heavenly that it mitigates the film's flaws. So what if it's all a little off? In the end, Mamma Mia! manages to move you with its unabashed exuberance. The eponymous tune does, after all, go: "Mamma Mia, how can I resist you?" For a few moments, anyway, it's the 1970s all over again. Bring on the disco ball.