Dearest Franz,
Thiele, of Berne, the trombone player, has just called on me, and told me that he recently visited you at Weimar, not knowing at that time that the place of trombone player would be vacant there. He asked me to recommend him to you, because, as a native of Weimar, he would like much to be employed there. I am cordially pleased to recommend him to you most warmly, not only for the sake of Thiele, but for that of your orchestra. He took part in 1853 in my famous May concerts at Zurich, and on that occasion gained, I may say, my whole heart by his enthusiasm. He had two very weak players with him, but managed to carry them along with him by his energy to such an extent, that in the passage one might have thought that one was listening to a whole host of trombones. Thiele, in short, is excellent, and known all through Switzerland as a trombone genius. I congratulate you on his acquisition. Do not let him escape you. What state I am in you may unfortunately see from the fact that a few days ago I felt bound in conscience and duty to ask Devrient not to rely on Tristan or me any longer. This was bound to happen, and there is an end for the present. Much luck to the Leipzig festival.
Richard Wagner
Source: Project Gutenberg eBook #4234, Correspondence of Wagner and Liszt — Volume 2, No. 292