They both deal with Broadway behind the scenes. Goldman's book is about one season, 1967-68. Riedel's book is much more sweeping and comprehensive. I wouldn't consider Reidel's book to be a successor to Goldman's. I think it stands on its own. IMO both works are quite different overall. Of course, both are also excellent and informative in understanding how Broadway works. It's just too pat an evaluation to state that Reidel's is a successor to Goldman's. It's much more than that.