09/08/2013 at 11:00 AM EDT
Four months after getting hitched, Keira Knightley
is thrilled to be a newlywed
"It's fantastic!" the actress, 28, tells PEOPLE at Saturday's premiere of Can a Song Save Your Life?
at the Toronto International Film Festival. "I'm very happy."
Knightley, who wed rocker James Righton, 30, last May in Provence, France, not only found a life companion
but also a personal music teacher. The Klaxons musician assisted Knightley in preparing for her role, which required her to play the guitar and sing.
"He helped me try to learn the guitar, and I don't think he'll ever do that again," she tells PEOPLE with a laugh. "I'm terrible, and he may have found it too stressful."
The Oscar-nominated actress (2005's Pride & Prejudice
) mastered the strumming skills just enough to play for her scenes, but has no plans on continuing to play the guitar. She would rather listen to her husband
play – and for good reasons.
"My fingers looked awful. They were callused and looked disgusting," she says. "I stopped playing and tried going back to it, but my fingers hurt too much, so I'm not going to do it again. I'll let him do all the playing."