Robert Lopez of 'Book of Mormon' writes song for 'The Simpsons'
Over the years, "The Simpsons"on Fox has engaged a few Broadway talents in guest spots -- Stephen Sondheim, David Mamet and Mandy Patinkin all have put it vocal cameos. The series even paid tribute to Bob Fosse in a few episodes, with an obnoxious choreographer character named Chazz Busby.