Józef Antoni Franciszek Elsner (sometimes Józef Ksawery Elsner; baptismal name, Joseph Anton Franz Elsner; 1 June 176918 April 1854) was a Polish composer, music teacher, and music theoretician, active mainly in Warsaw. He was one of the first composers in Poland to weave elements of folk music into his works. Elsner composed many symphonic, chamber, solo, and vocal-instrumental works, and works for the stage, including over 100 religious works (masses, offertories, oratorios, cantatas), eight symphonies, three concertos, three ballets, and thirty-eight operas. He is perhaps best known as the principal composition teacher of the young composer Frédéric Chopin. Life Józef Elsner was born 1 June 1769 in Grottkau (Grodków), Herzogtum Neisse (Duchy of Nysa), near Breslau (Wrocław), Kingdom of Prussia, to German Silesian Catholic parents Franz Xaver Elsner and Anna Barbara Matzke. His mother was from the famous Matzke family of Glatz, which had intensive contact with Czech culture in Bohemia. Józef Elsner was initially educated for the priesthood at Breslau's Dominican monastery school, St. Matthew's Gymnasium, and a local Jesuit college, but chose the music field. In 1832–37 he would compose nineteen religious pieces for Breslau Cathedral. After completing his studies at Breslau (Wrocław) and being a violinist at Brünn (Brno), in 1792 he became 2nd Kapellmeister at the German Opera in Austrian-ruled Lemberg (Lviv/Lwów). There, in 1796, he married Klara Abt, who died a year later. In 1799, with Wojciech Bogusławski, he went to New East Prussia (Prussian-ruled Poland) and became the principal conductor, first at the German Theatre, then at the Polish National Theatre in Warsaw. Elsner traveled to Paris, Dresden and Posen (Poznań), where he met E.T.A. Hoffmann. Together they founded the Musikressource in 1805. In 1802 he married a second wife, Karolina Drozdowska. Due to complaints that he preferred Germans, he resigned from theatre work. During his decades in Warsaw, Elsner's name and family life gradually polonized. Elsner's ethnicity should not be evaluated in terms of 19th- and 20th-century national identity, as he continued to refer to himself primarily as a Silesian. In 1799-1824 Elsner was the principal conductor at Warsaw's National Theater, where he premiered a number of his operas. Elsner also taught at the Warsaw Lyceum, housed in the Kazimierz Palace. Elsner taught the composers Ignacy Feliks Dobrzyński and Frédéric Chopin. There are also indications that he privately tutored piano composer and virtuoso Maria Szymanowska. Chopin dedicated to Elsner his Piano Sonata No.