Youtube Music Key & Youtube Mix and Youtube Radio
Is this something that would interest you and you might pay for? Youtube Music Key is in beta and you can put in your email address to request an invite. This is an ad free music service. The service is free for a 6 month trial and then will temporarily charge $8 per month before escalating it to the standard price of $10 per month. Other subscription music services include Spotify, Apple "Beats" and Google's Aindroid "Play."
There is information that Google is testing a Youtube Radio, which would work like Pandora and be competition for Pandora. I do like and use Pandora quite often, although I use the free service, but having everything in one place on Youtube sounds like a cool idea.
I cannot quite figure out what the Youtube Mix is, however. Apparently it is already available. Youtube mix automatically creates a playlist with many videos related to the video that's currently playing. That's cool. But where is it!?