Friedrich Demmer (1785 – 15 April 1838) was an Austrian operatic tenor, actor and director and possibly the first Florestan in Beethoven's Fidelio.
In December 1824 the actor Carl Friedrich Müller published a Musikalisches Angebinde zum neuen Jahre, "dedicated to his esteemed friend Mr. Friedrich Demmer, director of the "Theater an der Wien", which also contains a work by Ludwig van Beethoven: the waltz in E-flat major WoO 84, written on 21 November 1824.
[4] From September 1829 to 1834 he worked as a singer and then until his death as chief director of the Theater am Kärntnertor.
On 15 April 1838, "Mr. Friedrich Demmer, director in the Imperial and Royal Court Theatre next to the Kärntnerthor, aged 52, died ".
"[6] In retrospect, Ferdinand von Seyfried called him a "universal genius".