I pondered this, myself, when I listened to a piano cover of a song from a genre I loathe intensely: dubstep. Somehow, though, when it was being played on piano... it actually sounded nice and tranquil. So I started thinking... Is there any genre that is discordant to the point where you cannot just change the instruments to any of the songs and make them better?
Barring weird things like randomly generated sheet music, 99% of John Cage's works, and the like, is it possible to keep true to a genre that sounds inherently terrible and simply change the instruments to a song (eventually, you'd hit a good one) to fix it, for any given genre? Or is there something that just can't be saved?