For Adam Levine and Keira Knightley in 'Begin Again,' love is a song

Fans of Once, the 2007 musical romance that melted hearts and won an Oscar for Best Song, could be singing a new tune when Once director John Carney unveils Begin Again in July. Set in New York City instead of Dublin, the film features similar lonely souls who find each other through music. Mark Ruffalo plays a washed-up record exec, and Keira Knightley plays the heartbroken songwriter who sniffs at fame but might have the talent to redeem them both.

Knightley’s character, Gretta, is heartbroken because her boyfriend and musical collaborator, Dave, has become famous practically overnight, thanks to a Hollywood movie featuring his songs. Gretta is more a songwriter than a performer, and even though Knightley had sung before in a film, she wasn’t hired necessarily for her pipes. “[Carney] wasn’t looking for a voice that was going to carry a musical, and I know I don’t have that, but I think you can kind of get away with a lot more in folk music,” the actress says. “So we were kind of going for a talky-songy type vibe that we thought might be quite cool for her, and getting away from anything that was trying to pretend to be perfect.”

For Dave, on the other hand, Carney needed someone who not only had the voice but also the charisma of a star. He lucked out with Maroon 5’s Adam Levine, who makes his feature film debut. “Dave definitely needed to really sing and perform, and somebody just pitched in Adam with a bunch of names,” says Carney. “He did a tape and sent it to me, and it was just brilliant. He was so good and is very hard-working, and he doesn’t take himself too seriously, which is refreshing.”

“Adam is the classic frontman,” says Knightley. “He is a ball of energy. You just kind of switch him on and he just goes, and he just bounces off the wall for hours. It’s amazing being in a room with that much enthusiasm and that much energy.”

The film, which premiered at the Toronto Film Festival as Can a Song Save Your Life?, is playing at the Tribeca Film Festival on April 26. It opens in theaters on July 4.

In an exclusive clip from the film, Dave and Gretta enjoy better days together, singing the song “Lost Stars.”