"Backhaus was a wonderful pianist, not really representative of the German style. About him I can speak with real enthusiasm. He was more relaxed than most of them. I once heard him play the Chopin etudes and it was remarkable. In the first one in C major not a single note fell under the piano. It was fantastic. He heard me play Liszt's Feux follets and came up to me. “Horowitz,” he said, “I could never do that." But he was being nice. He could have if he wanted. I have often been asked what I consider the most difficult piece I have ever played. I can answer that quickly. It was Feux follets. The Liszt Don Juan is not an easy piece, either."