Is there anything Meryl Streep can't do? It would be tempting to say "won't do," but that would imply her appearance in Mamma Mia! is somehow shameless. Hardly. Watching the perennial Oscar nominee bounce on a bed like a teenager, kick out her legs, roll around on the ground, and sing her heart out -- without a trace of hesitation -- is another redefining moment for one of Hollywood's most treasured actresses. We know she's a performer with guts, but it never hurts to be reminded. On the whole, Mamma Mia! joyously reminds us how musicals -- especially those set on lush Greek islands -- can transport an audience to delicious realms of pure escapism. The whole cast fully commits, from the logical choices (prancing diva Christine Baranski) to the surprises (stiff-by-design Colin Firth) to the fresh-faced newcomers (charismatic Amanda Seyfried). In their hands, these songs have the same gusto ABBA must have felt when first writing and performing them. In some cases, gusto alone may not be enough, and Mamma Mia! likely works better for those not comparing the performances to the soundtrack of the popular show. For one, Pierce Brosnan, another plucky outside-the-box choice, seems to have more singing responsibility than he can properly carry. And a small amount of the choreography is inferior, such as the inert staging of Streep's solo "The Winner Takes It All," in which Brosnan is left trying to figure out what to do with his hands. Some of this can be blamed on stage director Phyllida Lloyd's inexperience with this particular medium, but in her first feature film, she's far more deserving of credit than complaint. It's hard to imagine anyone not feeling the rush when an entire village of women comes together to sing "Dancing Queen," finishing with a group plunge into the Aegean.