Disklavier

Hi, i have downloaded some of the piano competition midi files 
to my Mac and have tried making floppies for the disklavier, but 
they won't play. comes up as "unformatted disk." I have tried 
formatting the disks as Mac 800k, proDOS 800k, and 
proDOS720k. None of these work. Am I missing something?

Thanks!

Tony