Stephen Sondheim was the most highly regarded composer/lyricist for the musical theater in his generation. Having his first musical produced on Broadway in 1957 and his 14th in 1994, he straddled two eras. The broadly popular musical theater of his early years gradually became a more insular art form, addressing a smaller, more dedicated, more serious audience. This jibed perfectly with the composer's own tendencies. In a sense, he was to the world of show tunes what Bob Dylan was to that of pop songs, a songwriter who turned the genre to more mature and intelligent concerns a...