Adam Levine would turn his The Voice chair around if Keira Knightley auditioned.

The stars appear alongside each other in musical movie Begin Again, marking Maroon 5 singer Adam's first big-screen appearance.

Keira plays a wannabe musician, meaning she had to step out of her comfort zone and show off her vocal talents. Luckily The Voice US judge Adam had some supportive words to make Keira feel at ease.

"He kindly said that if I sang on The Voice, he'd turn his chair around - but I know he wouldn't," she laughed to British newspaper Metro.

The 29-year-old added that she didn't need to help movie newbie Adam settle in on set. He was apparently a complete "natural" and always full of energy.

Adam, 35, might have been impressed with Keira's singing, but a career change isn't on the cards for the actress.

"It was fine, but I wouldn't necessarily do it again," she mused when asked if she enjoyed performing. "It's not really what I do for a living but it was interesting. People who are singers - that's how they naturally express themselves, how they think, and it isn't for me."

However Keira isn't afraid of a challenge. Having appeared in numerous period films including Pride and Prejudice, The Duchess and Anna Karenina, the star has to work hard to secure roles in films set in the present.

"I'm definitely very high up the list for English period roles," she said. "I have to fight more for the contemporary naturalistic roles because it's not what I'm known for. I'm further down the list for those, which is fair enough."