Heinrich Dorn

Dorn became well known as a conductor of opera, and held theatre posts at Königsberg (1828), Leipzig (1829–32), Hamburg (1832), Riga (1834–43), and Cologne (1844–8). In 1849, he became co-conductor, with Wilhelm Taubert, of the Berlin Hofoper - a post he held until 1869.
Dorn taught counterpoint to Clara Schumann and Robert Schumann, and was a friend of Franz Liszt. He was a harsh critic of Richard Wagner but was persuaded to conduct the opera ''Tannhäuser'', in 1855. He also wrote an opera ''Die Nibelungen'', based on the Nibelungenlied, in 1853, many years before Wagner completed ''Der Ring des Nibelungen''.
Dorn died in Berlin in 1892. Provided by Wikipedia