Fidelio

Fidelio (Married Love) is an opera in two acts by Ludwig van Beethoven, his only work in this genre, with libretto by Joseph Sonnleithner and Georg Friedrich Treitschke. It was composed between 1804 and 1805, revised in 1806 and once more in 1814. The original three act version premiered on 20 November 1805 at the Theater an der Wien in Vienna; the first revised version (in two acts) also premiered at the Theater an der Wien on 29 March 1806 and the second revised version premiered on 23 May 1814 at the Kärntnertortheater in Vienna.