This is the first study of the musical activities of Empress Marie Therese, one of the most important patrons in the Vienna of Haydn and Beethoven. Building on extensive archival research, including many documents published here for the first time, John A. Rice describes Marie Therese's activities as commissioner, collector, and performer of music, and explores the rich and diverse musical culture that she fostered at court. This book, which will be of interest to musicologists, historians of artistic patronage and taste, and practitioners of women's studies, elucidates this remarkable woman's relations with a host of professional musicians, including Haydn, and argues that she played a significant and hitherto unsuspected role in the inception of one of the era's greatest masterpieces, Beethoven's Fidelio. Other composers discussed include Domenico Cimarosa, Joseph Eybler, Michael Haydn, Johann Simon Mayr, Ferdinando Paer, Antonio Salieri, Joseph Weigl, and Paul Wranitzky.