The organ registrations will not effectively play on your computer - a MIDI organsound is substituted.
The MIDI sounds from the PR300 will play only certain variation numbers. Otherwise your sound card and/or sound player will make a substitution.
Use the listening function to see what it sounds like only. If you want to hear the real thing, download it to a floppy disk and take it to the organ and PR300. See about downloadign on the previous page or click here: