Simpson collaborated with Hans Zimmer, as a featured soloist and contributing writer on the film score for the 2009 film "Sherlock Holmes", directed by Guy Ritchie. The score was nominated for the 2010 Academy Award for Best Score. She also collaborated with Damian Marley to score the documentary "Bouncing Cats", a film that follows one man's efforts to use dance to empower youth in war-torn Uganda. She worked with Dave Stewart (her manager), and co-wrote the theme song for the charity, Stand Up to Cancer.