The composer Johann Michael Haydn is the brother of Joseph Haydn. Like his more famous brother, he was a choirboy at St. Stephen's Cathedral in Vienna. Later he worked as violinist and episcopal bandmaster in Oradea. For over 43 years, from 1763, he was court composer and organist in Salzburg. He composed over 360 secular and sacred works. His choral works are especially well known. His compositions were not published during his lifetime, but circulated in handwritten copies. The astonishingly large number of Johann Michael Haydn's handwritten music manuscripts in the BSB come mainly from the Hauber Collection. Johann Michael Hauber (1778-1843) was pastor in Munich, from 1818 court preacher, from 1841 provost of the Theatinerkirche St. Kajetan. He wrote widely distributed prayer and edification books, supported Caspar Etts efforts to revive classical polyphony in church music and collected historical music manuscripts. Part of Hauber's music collection was taken over by the court library as early as 1821. It comprises some 450 music manuscripts and printed music, the most important part of which are the 196 autographs and copies of works by Johann Michael Haydn.