Appreciating and liking are two different words. Even if you don't like Jazz, to understand music you have to appreciate/respect the predecessors of modern music. If you don't like to listen to it, whatever, that's a whole different story.
Couldnt have said it better myself.
Modern Music is a cumulation of all sorts of music of the past, Jazz, Blues, and if you want to go into classical music its the style of the Romantic period. The music around us did just fall out of Wolfgang's ass, it was shaped, molded and twisted into what it is today. For example i'm listening to music and i pretty much know for a fact that if Men like Tchaikovsky or Rachmaninoff didn't exist, neither would muse.
