Richard Crouse

Near the end of “Begin Again,” the new musical romance from “Once” director John Carney, record producer Dan (Mark Ruffalo) instructs a guitar player, who is also his daughter (Hailee Steinfeld), to “keep it simple.” It seems director Carney took the advice as well, using the KISS principle—Keep It Simple Stupid—in the telling of this uncluttered story of redemption and pop songs.

When we first meet Dan he’s having a bad day. His estranged daughter is mouthing off to him, he gets fired from the label he helped create and even his car breaks down. The day—by this time it’s night, actually—improves when he stumbles into a bar to drink his blues away and hears Gretta (Keira Knightley) singing a sad song from the stage. In his mind’s eye he hears a hit, a song that could make her a star and give him another shot at relevancy.

Before he can begin again, however, he must help Gretta get over her ex-boyfriend, up-and-coming rock star Dave Kohl (Adam Levine)—he’s the kind of guy whose voicemail says, “It’s Dave. I’m probably doing something awesome so I won’t get back to you… ever.”—and her distrust of the trappings of fame.

“Begin Again” is as much about the love of music and it’s ability to heal as it is about the various relationships it essays. Carney is covering familiar ground here. His film “Once” breathed the same air, but it’s rarefied air, and he pulls it off with panache.

For instance, Gretta and Dan bond over a shared iPod filled with their favorite songs. Taken by the music they have a “we have to dance right now” moment, but it’s done with a twist when they go to a club and dance to their own music courtesy of their iPod earphones while everyone around them literally dances to the beat of a different drummer.

Ruffalo brings considerable passion to the role of Dan, an “I’ve-been-down-so-long it’s-looking-up-to-me” kind of guy. He’s a walking cliché, a record man who got eaten up by the business and a rough personal life, but Ruffalo gives him a soulfulness that’s very winning.

Knightley looks like an undiscovered indie darling, bringing a delicate but steely sensibility to her performance and the songs that help tell the story.

“The Voice” alum Levine and CeeLo Green (as a successful musician who owes Dan a favor or two) lend some music industry cred to their roles, but the heavy lifting, acting wise, is done by Ruffalo and Knightley.

“Begin Again” is a self contained story with a beginning, middle and satisfying end, but sets itself up for a sequel in the subtlest of ways. Dan comes up with the usual idea of recording Gretta’s album outdoors to get a real taste of New York in the grooves. After successfully setting up under the Brooklyn Bridge and in Central Park, Gretta suggests they could expand their horizons and make records on the streets of several other European cities. I’m not sure if that’s enough to build a franchise around, but I’d sure like to spend some more time with these characters.