超絶技巧練習曲
Egon Petri was horrified by the piano roll recordings when they first appeared on vinyl and said that they were a travesty of Busoni's playing. Similarly, Petri's student Gunnar Johansen who had heard Busoni play on several occasions, remarked, "Of Busoni's piano rolls and recordings, only "Feux follets" (no. 5 of Liszt's "Transcendental Études") is really something unique. The rest is curiously unconvincing. The recordings, especially of Chopin, are a plain misalliance".