Even those allergic to musicals may be won over by Once, a tender-hearted Irish romance with songs by Czech Republic–born Markéta Irglová and Frames frontman Glen Hansard. (The film's director, John Carney, actually used to play bass in the group.) The trick here is that Irglová and Hansard also play the leads; because their characters are shown busking, writing music, or rehearsing, the songs are smoothly integrated in the film. The overall acoustic mood won't surprise fans of the Frames--some tracks ("Say It to Me," "When Your Mind's Made Up") have even popped up on the band's albums, though the arrangements are more pared-down here, befitting the scruffy, street-musician setting. Being the lesser-known entity, Irglová feels like a revelation; she sounds a bit like a folkie Björk on "If You Want Me," and her song "The Hill" is downright heartbreaking. Irglová and Hansard had already made the 2006 album The Swell Seasontogether, so their collaboration here feels really organic--they sound particularly good together on the title track, for instance. Now that's the kind of magic you want from musicals. --Elisabeth Vincentelli