f resource viewer has problems opening that file it usually means that keygen's exe is packed. In that case easiest way is to launch keygen, now launch PE Tools, find keygen in the list, right-click on them and choose "Dump full..." and save dumped exe. This exe won't launch if you try to launch it, but it usually has all resources. Now open dumped exe with resource viewer. (You can try to use Quick Unpack instead of PE Tools if you wanna get working unpacked exe

2. Usually music is in "RC Data", "MUSIC" or "XMMOD" resource type. As you can see on the picture above music recourse has some junky bytes at the beginning. XM module starts with words "Extended Module:". Now just right-click and save it and do not forget to rename it to proper extension (xm, mod, s3m). If module has some junky bytes(like on the picture) just delete it with your favorite hex-editor:

Delete, save it, try to play it. Enjoy!