The libretto is an integral part of every opera, but it is also a text in its own right and therefore able to be viewed both in isolation, as literature, and in conjunction with the music, for which it serves as a foundation. In this book, Nancy O. Chamness presents a thorough and innovative analysis of the origins of Busoni's "Doktor Faust" libretto, both in terms of Busoni's development of the text through several revisions and in terms of its place in the literary tradition of the Faust legend, including Goethe's "Faust" and the Faust puppet plays. She then applies this analysis to understand how the libretto functions as a literary text, as an open drama, and as part of the music and action of the opera.