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 to be broadcast in the USA, over the NBC radio network, in December 1944, by the NBC Symphony Orchestra, featuring soloists from the Metropolitan Opera (though a shortwave broadcast of one act, conducted by Toscanini, had earlier been relayed from a 16 August 1936 performance at Salzburg.) Divided into two consecutive broadcasts, the 1944 performances were later issued by RCA Victor on LPs and CDs. "Fidelio" was the first opera performed in Berlin after the end of the World War II, with the Deutsche Oper staging it under the baton of Robert Heger at the only undamaged theatre, the Theater