Keira Knightley Finds Singing "A Frightening Experience"

London, England (BANG) - Keira Knightley says shooting her new movie was the most frightening experience of her life.

The actress had to sing in 'The Edge of Love', in which she plays Vera Philips the lover of Welsh poet Dylan Thomas, and admits she found it incredibly tough.

Keira said: "I did some lessons with a voice coach because I can't sing. It was live. There were 100 extras and the director John Maybury was like, 'Now you're going to sing.' "

"I've never been so frightened in my entire life. I never want to do it again. I don't want to be a rock star."

In the film - which also stars Sienna Miller, Cillian Murphy and Matthew Rhys - Keira sings 'Blue Tahitian Moon', as well as renditions of 'Maybe It's Because I Love You Too Much' and 'Drifting And Dreaming'.

'The Edge of Love', which was written by Keira's mother Sharman Macdonald, is set during World War II and is due for release on June 28.