Kaspar Karl van Beethoven, Brief an Breitkopf & Härtel in Leipzig, Wien, 12. Februar 1803, Autograph

Karl van Beethoven informs the publisher Härtel in Leipzig about the status of Artaria's pirate copy and sales of op. 29 through different Viennese music dealers. Karl writes with great satisfaction that he has brought about a royal decree which will prevent pirate copies like this in the future (we know of no such decree).

Karl mentions that his brother Ludwig is now employed by the Theater an der Wien, "he is writing an opera and is in charge of the orchestra, can conduct when necessary because a conductor is there for every day. He took on this position mainly so that he has a choir for his music". Although the opera to which Karl refers was already a fixed project, it is doubtful whether Beethoven already had a libretto in February and whether he had already begun work on the composition.

It was only at the end of 1803 that he was definitely working on Emanuel Schikaneder's libretto "Vestas Feuer"("The Vestal Flame"), which he gave up only a few months later due to its inferior quality in favour of Fidelio.

Finally Karl writes to whom the Variations opp. 34 and 35 are to be dedicated.