I guess Bart has made some very intelligent guesses!

I did sneak a look on the stage but sorry to say did not write anything down, so can't remember in any great detail now. The black strip above the keys was maybe fabric and I think someone said it was a port for the bass, but maybe the bass ported elsewhere so cannot be sure about this. The demo was through large monitors, not the built in speakers.

However to the right of the black strip was a section with tape recorder like controls, play, stop, previous track, next track, etc and a little jewel door for the flash card. This also had a lighting effect which you can just see in this picture. So this section must control audio or files on the flash card presumably. This was the 'Star Ship Enterprise' looking effect.