Maroon Five singer Adam Levine and actress Keira Knightley star in the upcoming movie Begin Again. To make the film, each had to step out of their comfort zones into a very different trade – Levine left the comfort of music to tackle acting and Knightly became a musician for her role – something she said terrified her.

“I kept telling her she was great and she wouldn’t believe me, and she told me that I wasn’t bad at acting either but I didn’t believe her, so it was perfect,” said The Voice coach.

“I was completely terrified,” Knightley said. “I didn’t anticipate being as frightened as I was. I said yes to doing it and I was, ‘Oh, it’s gonna be fine, it’s gonna be fine,’ and then suddenly I found myself in a studio with real people who did it for a living and I was like, ‘I don’t know what I’m doing. I’m pretending.'”

Now in HD: 'Begin Again' Trailer With Mark Ruffalo and Keira Knightley http://t.co/yyOokM3Y4e pic.twitter.com/VlNwwWySE0

— The Film Stage (@TheFilmStage) March 28, 2014

– @TribecaFilmFest celebra su gala de clausura con dos looks couture de #KeiraKnightley // http://t.co/9ZKTu4qRVq pic.twitter.com/z42I7sXAQl

— Vogue Mex y Latam (@VogueMexico) April 27, 2014

Levine said he loved his leap into the unknown.

“My experience was so much fun,” he said. “It made me kind of start to like it a little bit, but I don’t know. I don’t think you can really make those bold declarations, but we’ll see.”

The film, which also stars Mark Ruffalo, Hailee Steinfeld and Catherine Keener, was screened Saturday at the Tribeca Film Festival and opens in the U.S. in July.

Don't miss #KeiraKnightley and @adamlevine in the romantic comedy, #BeginAgain – in cinemas August 7! pic.twitter.com/gm4MxfnfUi

— Roadshow Films (@RoadshowFilms) April 26, 2014

Levine, 35, showed up at the screening with fiancé Behati Prinsloo, a Victoria’s Secret model, with whom he started dating in 2012.

The couple announced their engagement in July 2013.

@adamlevine & @BeePrinsloo at @TribecaFilmFest today for the #BeginAgain airing! Photo by @LovelyLinda1823 pic.twitter.com/t0fQHYUCSg

— Maroon 5 (@M5NewsRoom) April 26, 2014

“She makes me the best person I can be,” Levine said Sunday. “She’s the best in the world.”

Image via Wikimedia Commons