The Partner program includes participation in YouTube's Music Key beta. This subscription service launched in beta form in November, and it provides ad-free playback, Spotify-like playlists, offline and background music options, and access to the full Google Play music library.
The more musicians and artists that use YouTube to promote their work, the better that is for YouTube's future plans. Music Key needs musicians to function as promised, and YouTube for Artists is similar to analytics services offered by Spotify, for example. YouTube already extends this type of support structure to video bloggers and personalities, and it looks like music is the next big bet.
source: engadget.com by Jessica Conditt