[...]We will do the C minor prelude of Chopin. ( A student performs this piece .)
Probably some of you were shocked by this "E natural" he played; whether it should be "E flat" instead is not a matter we can settle, because editions differ. I have a photocopy of Chopin's manuscript, and it says "E natural" , but the advocates of "E flat" assert that Chopin simply forgot to write the flat in. This is a dangerous way to prove something, especially since you will see if you look at the facsimile of the preludes how really exact Chopin was.[...]