When a book claims Hal Prince directed Assassins and Flora the Red Menace, that Richard Rodgers and Alan Jay Lerner created On a Clear Day You Can See Forever (while, bizarrely, acknowledging that Burton Lane wrote the music--the implication being that Rodgers helped write the book or something; ugh, Rodgers and Lerner tried to collaborate on that show when it was called I Picked a Daisy but they couldn't work together and Rodgers had nothing to do with the show as it came to Broadway). Somehow, the author thinks Tom O'Horgan was staging musicals on Broadway in the mid-sixties, and he puts O'Horgon in the same category as Bob Fosse and Gower Champion, despite O'Horgan not being a choreographer-director, and of course of a completely different kind of theater that either of those two...he didn't stage a Broadway show until late 1968. There's an odd flub when the author refers to "Madam Rose" by which he means the character in Gypsy often referred to as Mama Rose, though in fact the character is simply named Rose.
The book gives long bios on just about everyone associated with the various productions, which at times it feels like padding. Between false info, dull explication and a sort of aimless narrative, I don't think the book has much to recommend it.