I bought Parappa the Rapper 2 today at Eb for only $10, but for some odd reason the game has no sound. I have my PS2 hooked up to my receiver with an optical cable. Everything is hooked up right and the sound works on other games. Did I get a bad copy of the game?

believe it or not, the optical cable is the source of the problem. The same thing happened to me when i rented this game, for some reason, the game won't play the audio through the optic cable (kinda weird since it is a game based on audio). You can solve this problem by unplugging your optic cable and connecting regular red and white audio jacks and it should work, you might have to configure something in the PS2 menu but i don't think so. hope this works for ya. this is the only game i have ever encountered this situation, its pretty weird.

edit: You might not have to actually unplug your optic cable, just plug in the RCA red and white ones and that may work, if not then unplug it.

It's okay. You don't really need sound in this game.

The reason you don't get sound through the optical cable is because Sony doesn't want you to record the music using a MD player. They'd rather you buy the game soundtrack instead.