Abstract
The manuscripts of four operas, one melodrama, two cantatas, one motet, two instrumental concertos, six symphonies, and six compositions for wind instruments by the composer Johann Joseph Rösler (1771-1812) are found in the archives of the Prague Conservatoire. Although Rösler gained recognition as a composer and piano virtuoso in Prague and Vienna, left behind more than 200 works, and earned the prestigious position of Kapellmeister to the important musical patron Prince Franz Joseph Maximilian von Lobkowitz, his music was nearly forgotten in the twentieth century.
Moreover, already during the nineteenth century Rösler's name was often confused with that of Anton Rößler (1746-1792) or Rosetti, the Kapellmeister at Ludwigslust, who belonged to the previous generation. Rösler usually signed his compositions as Joseph Rösler, but his name also appears in a number of other forms (Joseph Rössler, Rößler, Röszler, or even Giuseppe or Giuseppe Giovanni Roesler).
We owe most of what we know about his life to an article in the monthly journal Monatsbericht der Gesellschaft der Musikfreunde des Oesterreichischen Kaiserstaates (1829), later supplemented by Constant von Wurzbach. A valuable source of information about Rösler's music is the thematic catalogue Repertorio di tutte le mie Composizioni incominciando dallʼanno 1796.
Parte 1ma, written in his own hand and dated 1796-1809. The 117-page list is written partly in Italian and partly in German, and contains notated incipits.
Besides dating, it also provides valuable information about the first performances of certain works (names of performers, places of the performances, names of persons commissioning compositions). On its basis, it was possible not only to identify Rösler's autographs reliably (the long-lost Piano Concerto in E Flat Major among them), but also in combination with information contained directly in the scores and in the period press to add something to our still incomplete mosaic of knowledge about Rösler's life and work and his involvement in the musical life of Prague and Vienna.