First-time filmmaker Kate Barker-Froyland trusts the silences that occur when two people aren't talking. That's a good thing. What's not so good is when the talk grows enervating. That happens when Franny (Anne Hathaway), studying anthropology in Morocco, returns home to New York to see her brother Henry (Ben Rosenfield), a busker who's been in a coma since a cab hit him. It's Franny's plan to revive Henry by bringing him the sounds and smells that inspired his music. She also befriends and beds James Forester (Johnny Flynn), Henry's rock icon, which seems, well, a little creepy and a lot contrived.
Despite the delicate shadings Hathaway brings to the role, Song One moves inexorably from wan to wearying. Hoping to capture the bittersweet vibe of the 2006 cult hit Once, Barker-Froyland injects the fragile plot with songs written by the indie-rock duo Jenny and Johnny. Hathaway stares longingly as Flynn sings, but Once, I'm afraid, is enough.