In almost every edition (and consequently most performances) of Chopin's Sonata in B flat Minor, Op. 35, there is a serious error that makes awkward … - Charles Rosen

The relation of the performance of music to sound is complex and ambiguous: this is what makes possible Mark Twain's joke that Wagner is better than he sounds.

I do not mean that it is not worthwhile to attempt a revision of the canon or that no success is possible. A few valuable minor changes have been made to our sense of the basic material of the history of music, and other alterations are still waiting to take hold. Gesualdo has not displaced Monteverdi or Palestrina but has won a permanent place; on the other hand, the attempt to convince us that Telemann is a major composer appears to have been abandoned. Alkan has not had the breakthrough his admirers had hoped for. Attacks on Tchaikovsky have not had much success in removing his music from the repertory; his credit with performers has not changed a bit.

Critical evaluation was transformed into understanding, and criticism became not an act of judgment but of comprehension.