Sorry if this is old news, but I was really surprised when I stumbled upon this story on YouTube. It seems there are a lot of gamers who haven't heard about this either. Apparently sound designer Kazumi Totaka has been hiding a song in Nintendo games for many years, as kind of an Easter Egg, dating back to at least 1992. There's a possibility that it's in every game he's worked on so the search is on to find more. Learn more about it here: Totaka's Song
its first appearance was in X for the gameboy i think , or was it Faceball 2000, somewhere in the code.