Whenever The Voice judge Adam Levine is blown away by a singer’s performance, his typical reaction is to spin around wildly in his chair. During the filming of Begin Again, Levine didn’t have access to his trusty swivel chair, but if circumstances had been different, the Maroon 5 frontman says that he would have done plenty of spinning over Keira Knightley’s singing in the film. “I would, I would definitely [swivel],”; he tells ET Canada’s Rick Campanelli. “Let me tell you something, she’s really great.”;

But according to Knightley, Levine’s praise should be taken with a grain of salt. “When he said, I would turn my chair around for you, I said no you wouldn’t. Don’t be ridiculous. I can’t take a compliment, clearly.”;

In the film, Knightley and Levine play college sweethearts who breakup after Levine’s character becomes a famous rock star and has an affair with a groupie. As it happens, Knightley’s character also has musical inclinations, and—after being spotted by a disgraced record executive (Mark Ruffalo) at an open mic night—she too gets a chance to make it big.

It’s a story that Knightley says anyone over the age of 18 should be able to relate to. “I think it’s impossible for any adult not to [relate],”; the 29-year-old star offers. “Because it’s impossible that you haven’t either had that relationship, or that moment in your career where you think that everything is absolutely set and suddenly something happens and you’ve landed flat on your face and you have no idea who you are or where you’re going.”;

Unlike the overnight success story that he plays in the film, Levine says that his own success came far more gradually. In fact, Levine says he didn’t realize the full extent of his fame until relatively recently. “We were shooting a video for one of our songs on our last record [Maroon Five’s upcoming V],”; Levine recalls. “And we’re shooting and I’m driving a car, and a bus pulls up and it’s got a thing for The Voice, and we’re shooting, and I’m supposed to be very serious. And I look over and my face is staring at me with the bus. I just look over at the camera and go “Yeah.'”;

Watch Rick Campanelli’s full interview with the cast of Begin Again below!