His [Chopin's] public appearances were few and far between, and consisted in concerts given in the ' Salon Pleyel,' when he produced his newest compositions, the programme opening, I think, invariably with Mozart's Trio in E major, the only work by another composer which I ever heard him play. He was so entirely identified with his own music that it occurred to no one to inquire or even to wish to know how he would play, say, Beethoven's sonatas. If he was well acquainted with them remains a moot point.