It took me two tries to read this book, because the writing style is not very clear. It presumes some familiarity with the musicals themselves. (In one chapter, they "explain" the scene leading up to a big dance number as "the train got stuck in the desert so they couldn't do the show." What? It was set in the desert and the audience was only people on the train? What?) Some chapters have pages of verbatim quotes that really could have used more explanation and clarification. But the author seems like more of a producer than a writer, so I guess we can cut him some slack in that department, because he seems to know most of the people he's writing about.
I most enjoyed the parts talking about "Guys and Dolls", because I've both seen it onstage and been involved in a production of it. I knew about the character who is supposed to be fat, and what lines in the musical talk about him being fat, and so the angst of how to have a skinny guy play him made sense. (In our low-budget college production, we had a skinny actor with a pillow stuffed under his shirt playing him).
It was cool to read about what goes on behind the scenes in the theater. I learned that musicals can be workshopped for years before opening on Broadway, that many people train in acting/singing/dance but there are people who get hired and do well with almost no formal training, and that reviews matter much more to theater than they do to movies (because theater is so much more expensive that people won't take a chance on a production that was panned by critics, unlike with cheap movies). I learned that shows have previews so that they can work out the kinks before they are reviewed on opening night. (Though I am still somewhat mystified how a show can be workshopped and previewed and then open on Broadway and still be a flop ... if they have plenty of time to test drive it in front of audiences, wouldn't they know that audiences wouldn't like it?)
What really struck me was that there seemed to be a whole generation of men in theater who died of AIDS. Sure, I've seen Rent, and I know that there are lots of gay men in theater, but I never really made the connection until reading in this book that "he was working on it with so-and-so, but then so-and-so died of AIDS and so did these three other people, so the project changed." And that seemed to happen multiple times. It was chilling.