BERLIOZ Hector (1803-1869). L.A.S. " H. Berlioz", [Paris around December 17, 1852], to Bernhard COSSMANN; 2 pages in-12 .Unpublished letter on a musical evening. The German Bernhard COSSMANN (1822-1910) was cellist at the Paris Opera; he had gone a little before to Weimar with Berlioz; he was also professor of cello at the Moscow Conservatory. Berlioz mentions here the young Czech pianist Wilhelmine CLAUSS, and the Belgian violinist Henri VIEUXTEMPS, all of whom will take part in the musical evening of 19 December at Berlioz's home, who will write to his friend Duchesne: "The other evening we did trios at my house, with Vieuxtemps, Mlle Clauss and Cossmann. ... They played Schubert trios for us, in which there are some admirable and new things ". " We would like to do some music on Sunday. Miss Claus and Vieuxtemps will come, and you would be kind enough to join them to perform the trio in mi♭de SCHUBERT you probably know. In case you don't make me say anything, I'll count on you. Then be good enough to send your instrument " ... Correspondance, t. [IX, New Letters], no. 1540bis (excerpt ).