Try asking
Hoobastank.
I don't know what kind of genre of music you are looking at including in the game, but if you want something from a rock music genre, just try asking them.
We asked them if we could use their music in our
flash animation of our team's
website, and they graciouisly let us use a part of a song.
(Thanks Hoobastank!!)
Of course we included a special thank you for the use of their tunes on our
copyright page.
I don't know how the permission was gotten, but it may be a different battle(?) if you want to use their music in a game that you plan on selling?
I know that we don't use the website to sell anything, so maybe that's why it was cool with them to let use use a sample.
I'm assuming you are going to try and sell this game eventually?
Anyways, it never hurts to ask.