Craig Brougher hit the nail on the head -- as he usually does -- in two
remarks he posted last week.  He is right that there is no connection
between tracker organs and tracker bars, except the coincidental use of
the word "tracker" -- used, however, in different senses.  (Incidentally
I think there is no deeper or more esoteric meaning to the term "tracker
bar" than that the bar "tracks" the music roll; one needn't drag in modern
MIDI-like concepts of note-position tracks to explain the term (KISS is
a good motto here) ).

 [ "Incidental" is right!  I've concluded that the roll-tracking system
 [ on 88-note pianos is the result of the poorly designed chuck and 
 [ flanges.  You don't see roll-tracking systems on nickelodeons and
 [ organs, do you !  -- Robbie