so who has to enforce it? An efficient system has you paying your $30 or $40 to get your copyright, wrap your song in DRM, and send it out to find buyers. Maybe perform it at concert halls and hope for radio (or internet radio) air play. Who knows - and then people come to your site to buy the song. What happens to that model if everyone can copy it for free and you have to go find them and then what, sue them?
Isn't it simpler if you could just upload your song into an Audible Magic or Gracenote database, and then YouTube knows it's copyrighted, and can match it and take it down if it's not authorized? Gracenote recognizes your cd when you put it in itunes - why not recognize it on Youtube?