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 … - Charles Rosen

The relation of tonic to dominant is the foundation of Western triadic tonality. The attempt of the early nineteenth century to substitute third or mediant relationships for the classical dominant amounted to a frontal attack on the principles of tonality, and it eventually contributed to the ruin of triadic tonality. This ruin was accomplished from within the system, however, as mediant relationships were essential to tonality as conceived in the eighteenth century.

Sonata form could not be defined until it was dead. Czerny claimed with pride around 1840 that he was the first to describe it, but then it was already part of history.

When I was a small child, The New York Times received every new creation of Igor Stravinsky with hostility, but even then I knew, like everybody else, that he was the greatest living composer-and I knew it even without having heard much Stravinsky or even any of the more recent works at all. It is a mistake of music historians to rely too much on journalists and music critics to assess a composer's reputation, as we generally find a certain delay in their transmission of the more influential professional judgments.