From Wikipedia:

Jonathan Davis' first musical output outside of Korn was recorded as the soundtrack for the Queen of the Damned film. Originally, he was going to sing on the album, but due to contracts with Sony, he could not. So, he hired some of his musical peers to record the vocals. In the film, the songs are played by Lestat's heavy metal band.
http://en.wikipedia.org/wiki/Queen_of_the_Damned_Soundtrack_Album