The First Age. Source material ; The age of burlesque ; At the turn of the century.
The Second Age. The witch of the wood and the bamboo tree ; Victor Herbert ; The new music ; The variety show.
The Third Age. The structure of twenties musical comedy ; The structure of twenties operetta ; Dancing in the dark ; Blue Monday blues ; The Rodgers and Hammerstein handbook ; Something to dance about ; After West Side story ; The Sondheim handbook.
The Fourth Age. Devolution ; That is the state of the art.