Hmm, child of the 70's much (yep, I'm that old - 34) - this is reasonably amusing mashup of Stairway to Heaven and the theme from Gilligans Island. Actually, I'm not sure I'd really call it a mashup as it doesn't use the originals in themselves, but it's the song sung to the tune of Stairway. The end is cool.
Actually, on re-reading the link from Boing Boing, they do call it a proto-mashup. This actually came out as a single. Wonder what was on the b-side? Nothing about that at the blog this was posted on originally - http://libraryofvinyl.blogspot.com/ but certainly a fairly interesting history of the whole thing. Enjoy.