Shooting on 16mm in the months before he graduated from Harvard, Damien Chazelle makes a stunning debut with this tiny, almost monosyllabic narrative, which bursts open, unexpectedly, with the jazziest, most joyous musical numbers ever in an independent film. Here's the little Boston movie that could, with a pick-up on the Red Line, cool romance in Harvard Square, hot trumpeting at Wally's, and a large-scale tap-dance number à la Busby Berkeley after hours at the Summer Shack. Counterpointing the momentous music is the slight, on-and-off romance of needy Madeline (Desiree Garcia) and self-absorbed trumpeter Guy (Jason Palmer), their talk together being no more than a few swallowed sentences. Chazelle's influences are cinematic chestnuts: 1960s Godard, John Cassavetes's 1959 Shadows, MGM 1940s song-and-dance. But his classic sources glow anew, transformed by his keen eye and framed by his winning vintage sensibility.