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
Boris Godunov (opera) Boris Godunov (opera) Boris Godunov (, "Borís Godunóv") is an opera by Modest Mussorgsky (1839–1881). The work was composed between 1868 and 1873 in Saint Petersburg, Russia. It is Mussorgsky's only completed opera and is considered his masterpiece. Its subjects are the Russian ruler Boris Godunov, who reigned as Tsar (1598 to 1605) during the Time of Troubles, and his nemesis, the False Dmitriy (reigned 1605 to 1606). The Russian-language libretto was written by the composer, and is based on the drama "Boris Godunov" by Aleksandr Pushkin, and, in the Revised Version of 1872, on Nikolay Karamzin's "History of the