As a performer I can't help but think that if you could show up on site
and drop a keytop player on the piano they have there and make it play
MIDI files, it would be quite impressive to the folks who go there all
the time but never heard anything like that out of that piano.  In some
cases, it will be a piano no one ever heard anyone play before.  And no
one will fail to realize that it is much more than anything you can get
out of a loudspeaker.  So, is there anything like that?  I'm doing a
job on a broken keytop roll player and it seems best to ask now.

Lee Rothrock

 [ The QRS Playola keytop player does what you want.  A special version
 [ called the "Psalmist" was made to play the Hammond B3 organ, see
 [ http://www.qrsmusic.com/press_details.asp?rid=54  -- Robbie