I have a couple of PSX games (bust a move 4, Buster bros collection, megaman legends). My Super Slim runs them all, but a few of them lack game music, such as Buster Buddies in Buster Bro collection. I'm curious why. In the case of Buster Bros collection, the first two games run 100% fine with music and all. But the third game, Buster Buddies lack game music. There's sound for selection and shooting and stuff, but no background music. Is it the way the disc made? Or what?