A friend sent me this clip and I can't get enough of it. It is completely vocal (and manual, for the first part), no instruments used at all except those provided by the human body. I am clueless about vocal music--I couldn't carry a tune with a forklift--but even I can appreciate how intricate and detailed this interpretation is.
It doesn't hurt that it's one of my favorite songs from my childhood. I admit it. I'm hopelessly stuck in the '80's.