I don't think anyone would figure that out by just owning both consoles, lol. Although we don't have a Famicom Disc System, I know what the startup jingle sounds like, and I'm very familiar with the GameCube menu sound. It plays way to slow for anyone to be able to recognize it as the Famicom startup jingle. I'm guessing whoever discovered it did so via a video or sound editor, out of curiosity or by accident when editing a video.