In the US, once you pay an initial retainer, a layer will sometimes work on a contingency basis - meaning they get one third of the final settlement. Given that

In the US, once you pay an initial retainer, a layer will sometimes work on a contingency basis - meaning they get one third of the final settlement. Given that UMG is a rich target, and the claim seems very strong, you might find someone like that to drive it. Even if you do, it will be slow, agonizing, and ultimately less than it should be when you win.