rushing, ad infinitum
Things are always changing, and music is no exception. Music changes every day. There are new technologies, new sounds, new artists, people jumping around genres and doing their own things - all of these things and more will prevent music from every stopping its evolution. It might someday evolve into babies smacking metal pots with wooden spoons as the new rock or a boy trying to beatbox to the beat of a girl chewing an ice cube as the new rap/dubstep, but 'new' music will still spring up regardless of the circumstances.