I am just come from Wieck's, where Clara played admirably in one of Schubert's trios. Bach's Concerto for three pianos, performed by her, Felix, and myself, was very interesting; [...] You ought to have seen poor Felix accompanying a very inferior singer, and watched him as he sat on the stool of penitence, with thirty listeners around him. His eyes sparkled like those of a baited tiger, and you could have lit a candle at his cheeks, they burned so.