Keira Christina Knightley is an English actress and model. She began acting as a child on television and made her film debut in 1995.
This song is from the movie "Begin Again" which is a 2013 American musical comedy-drama film written and directed by John Carney and starring Keira Knightley and Mark Ruffalo...
There's another song (Like A Fool) and clip from the movie here:- https://www.youtube.com/watch?v=4mxDUyftF9k