I didn't even know the GAMECUBE startup sound was a meme.
Other than that, my guess would be that the sounds are all sequenced. Toru Minegishi once said that the startup sound was created by him. The other two are probably by him as well, as could be the menu theme (though that is a variation of the "Disk System Theme", as mentioned).
edited 1:34 PM EST February 23, 2010
by unknownfile at 6:22 PM EST on February 23, 2010
congratulations nenson on making a post that i found useful