Trailer Music Info on John Williams SiteMusic
JWFan.com has the following:
John Williams has already started working on his new film score, Harry Potter and the Prisoner of Azkaban (to be released on CD in May 2004), for which he has already composed a song, "Something Wicked This Way Comes", which can be heard on the film's trailer.
Frequent contributor Sue suggests downloading the audio from the site, as the lyrics come across a bit more clearly. Thanks, Sue!