I would personally say, just use it, and when you have the game finished or near finished, email/write the copyright owners. But right now the chances of you finishing it are not very big, and if you finish, the chances of making thousands are very slim.
So i would say, dont worry until you worry about giving the game out
And when it gets to the point of selling/giving out the software, music rights arnt cheap
you would have to make lots of money off of the software.
"people who wear clothing with tech themes for the purpose of gaining a social label are no different than teenagers who wear large sweatpants to look edgy"
-Wikipedia "Nerd"