This has to be one of the most insane and esoteric uses for Excel I have ever seen. This is courtesy of
Music thing: The Excel spreadsheet synthesizer
I have just blown an hour playing with this and trying to figure out how it worked. (Quite the three piper Eh Watson).
Totally insane, but it redifines the weirder limits of “Just Because We Can”.
Here is a direct link to the site. http://sunsite.univie.ac.at/Spreadsite/fourier/fourtone.htm