Since the release of the first Harry Potter book over a decade ago, J. K. Rowling's fantasy novels and the films based on them have broken many publishing and cinema records. Over the course of seven books, a simple story about a boy wizard becomes an epic tale of good-versus-evil, the fate of the world, and-of course-adolescent hormones. Given a long record of scoring sci-fi and fantasy films with Steven Spielberg and George Lucas, John Williams was a natural pick to create some musical magic. While creating this long record, however, Williams paid his dues. For years, he worked as an arranger and editor of other film composers' material, and as a studio pianist, he can be heard on the scores to several films, including "South Pacific" and "To Kill a Mockingbird."