I've long been curious about musical theater, how it began and how it's evolved over time. Broadway historian Ethan Mordden's book is a fingernail sketch of musical theater history that's informative but also a jumping off point to learning more. In my mind, musical theater emerged in the 1920s/1930s, but Mordden's book goes much further in the past beginning in the 18th century, and dedicating about 2/3's of the book to late-19th and early-20th century musicals before reaching the time period I'm more familiar with.
Musical theater in the United States grew from numerous influences including operetta from Europe, the homegrown minstrel show, burlesques (the theatrical spoof version, not the striptease) as well as the more prosaic musical play in which the theater's house band would perform tunes throughout the performance of a play. L. Frank Baum's adaptation of The Wizard of Oz as a musical extravaganza is noted as a key moment in the development of musical theater, which is amusing since Wicked is the biggest thing on Broadway 125 years later.
The early 20th century was also the period in which Victor Herbert became the preeminent American composer of operettas which typical had successful Broadway runs followed by extensive touring productions. Around the same time Florenz Ziegfeld Jr. established the musical revue as a centerpiece of American theater with his Ziegfield Follies from 1907 to 1931. Ziegfield also produced Show Boat by Jerome Kerns and Oscar Hammerstein, Jr., a groundbreaking show that incorporated music into the storytelling and characterization, as well as being racially diverse.
At last we reach the Golden Age of Musical Theatre, which Mordden frames with the "Rodgers and Hammerstein Handbook," the various "rules" that Richard Rodgers and Oscar Hammerstein followed in creating their game-changing run of shows in the 1940s, 1950s, and 1960s. Mordden also traces the big works and notable flops of George and Ira Gershwin, Rodgers and Hart, Irving Berlin, Cole Porter, and Lerner and Loewe. He uses a similar approach for musicals of the 1960s and 1970s but this time framed around the works of Stephen Sondheim.
It's not all surprising that Mordden is unimpressed by the megamusicals that have emerged since the 1980s (although he has kind words for some). I was more surprised at his distaste for the practice reviving musicals, which he considers lazy. In fact he's harsher on revivals than on "jukebox musicals," noting that as early as The Beggar's Opera in 1728, musicals relied on old music to tell new stories (personally I think it's more interesting to revive shows with new productions every so often than to have the same production run for decades with a rotating cast, but that's neither here nor there). It's too bad this book was published just before the opening of Hamilton because it would be interesting to see how Mordden thinks it fits in to the broader history.
Mordden's writing style tends to ramble, and as he's written extensively about Broadway history, I think he assumes the ordinary reader has a much greater existing knowledge of musical theater than I actually do. He is also highly opinionated about the various musicals and their productions, which is surprising since he could not have seen the majority of these shows (Mordden was born in 1947) that exist at best as imperfect cast recordings and with no real pro-shot films prior to the 1970s. An extensive discography at the end of the book (which also sometimes videography) is helpful, although it's written as a long essay, whereas I would find it more useful if it was a list of plays and their various recordings with Mordden's thoughts on each.