In addition to being an MMD subscriber I belong to a jazz cyberlist.
A recent posting there was directed to me but, not being at all
knowledgeable in this area, I could not comment.  Here is the relevant
part of the message :

 "Five or six years ago I visited a music museum in a town on the West
  coast of the Lower Peninsula of Michigan.  I can't remember the name
  of the town, or even the name of the museum, but I videotaped rather
  extensively there; if there is any interest, I could retrieve the
  videotapes and provide additional info.

 "One of the things that fascinated me there was an instrument called
  a Dixon Recording Piano (I think; again, the videotape could provide
  precise details).  This grand piano was an amazing instrument back
  in the 1920s.  It recorded on a perforated roll, but was capable of
  recording all the dynamics of the music.  It was extremely expensive
  -- I seem to recall that they cost $35-50,000, a vast sum at that
  time -- and only a small number were ever made, something like six
  to ten."

Can anybody provide more information about this instrument?

John Farrell
http://homepages.tesco.net/~stridepiano/