"[I believe] that dissonance can be as beautiful as consonance. [...] there is no reason for finding dissonance ugly except that we are accustomed to believing it so. Two discordant notes are merely a little closer together than two consonant notes. I believe that the human ear can be trained to dissonance and find it beautiful, and then the vocabulary of music will be doubled, won’t it?"
Arnold Schoenberg, 1913: