Fidelio by Ferdinando Paer (a score of which was owned by Beethoven). Beethoven published the 1806 libretto and, in 1810, a vocal score under the title "Leonore", and the current convention is to use the name "Leonore" for both the 1805 (three-act) and 1806 (two-act) versions and "Fidelio" only for the final 1814 revision. The first version with a three-act German libretto adapted by Joseph Sonnleithner from the French of Jean-Nicolas Bouilly premiered at the Theater an der Wien on 20 November 1805, with additional performances the following two nights. The success of these performances was hindered by the fact that
Fidelio a rival nobleman, Pizarro. In revenge, Pizarro has secretly imprisoned Florestan in the prison over which he is governor. Simultaneously, Pizarro has spread false rumors about Florestan's death. The warden of the prison, Rocco, has a daughter, Marzelline, and an assistant, Jaquino, who is in love with Marzelline. The faithful wife of Florestan, Leonore, suspects that her husband is still alive. Disguised as a boy, under the alias "Fidelio", she gains employment working for Rocco. As the boy Fidelio, she earns the favor of her employer, Rocco, and also the affections of his daughter Marzelline, much to Jaquino's chagrin. On