If you know even a little about Xanadu, you probably know too much about The Apple, the 1980 Euro-Trash Musical that came out before Xanadu. I briefly talked about this movie in my piece in Face The Music ELO podcast and in their final Xanadu episode.
Ken Anderson recently posted his thoughts on this "Mount Rushmore of Bad Musicals" (as described in the Cannon Picture doc, "Electric Boogaloo") in his blog, DREAMS ARE WHAT LE CINEMA IS FOR...
Good Luck with this one!
Don-O