Flammy
Shooting Down Idiots
This is definitely the best advice.I wasn't aware of any networks that allow you to use UMG songs.
I recommend you talk to a few networks, see what they offer you, and chose the one that bests fits you and your aims with YouTube.
I ended up talking with dozens of networks prior to joining my current network. I wrote up some of the experience here if you haven't seen it: yttalk.com/threads/i-just-got-partnered-i-did-my-research-have-you-done-yours-guide-advice.52842/
I ended up going with a small, exclusive high end network. It roughly doubled my CPM, more than making up for the rev share so I definitely am happy where I am. I only joined after talking with all those networks and asking about CPM info about them - these guys backed up their claim with actual numbers and from what I saw *is* the best.