Who sang in the movie Phantom of Opera?

The 2004 adaptation of The Phantom of the Opera featured the vocals of Gerard Butler (Phantom), Emmy Rossum (Christine), Patrick Wilson (Raoul), and Minnie Driver (Carlotta). For some of the performances Butler was dubbed by Broadway singer Anthony Warlow after it was deemed by Andrew Lloyd Webber and Joel Schumacher that some high notes sounded "strained". All of Rossum's vocals were her own.