I'm not usually a big SF fan (except for the fabulous works of Cory Doctorow, of course), and I was shocked when I read The Golden Globe by John Varley. From the jacket:

"All the universe is a stage...and Sparky Valentine is its itinerant thespian. He makes his way from planet to planet as part of a motley theater troupe, bringing Shakespeare--a version of it anyway--to the outer reaches of Earth's solar system. Sparky can transform himself from young to old, fat to thin, even male to female, by altering magnetic implants beneath his skin. Indespensible hardware for a career actor--and an interstellar con man wanted for murder..."

This is simply one of the best books on musical theater that I have ever read. The number of inside references to some of the classics of musical theater are simply too numerous too mention. I kept wondering why this book was published: How many SF fans are into musical theater? I would honestly read a chapter, and quickly flip to the front cover to make sure it was SF. God, what a great book. Go out and buy a copy today.