Score one for going home again. After misfiring with Begin Again, writer/director John Carney has turned back to the striving Irish of Once, his breakout hit. He's also hearkened to the pop of his youth, setting this boisterous tale of a Catholic-school garage band in 1985 and letting his 15-year-old singer/songwriter Conor (Ferdia Walsh-Peelo) adopt the sounds and personae of that era's synth-pop heroes. Carney's Dublin is troubled and hardscrabble, but this is an aspirational musical from a born crowd-pleaser, so don't expect an unflinching look at poverty — and don't expect the characters to ever stop looking like they're trying to prove it's 1985, with their frosted tips and denim pantsuits.
But Sing Street pleases, all right, and even occasionally hits on truth: At first Conor's band apes Duran Duran. Then his stoner older brother (Jack Reynor) hips him to more daring fare, and soon Conor shows up at school in full Cure regalia, even once smearing on a faceful of makeup. That doesn't go well for him, but Carney and Walsh-Peelo emphasize the character's strength rather than his occasional victimization. He's always defiant in the face of attacks on whichever self he's currently trying on. Carney is smart about how much creative kids draw on the cultural material around them as they will themselves into being; he's also smart about musical numbers. Sure, the songs (written by Gary Clark and Carney) sound too confident, too fully composed. But their borrowings are bold, sometimes comic, and the lyrics are perfect youthful notebook scribblings: "She's standing on the corner/ like an angel in disguise" kicks off the priceless pastiche "The Riddle of the Model."