Greetings -- I am always intrigued to read about the plentiful player
piano permutations described in MMD.  Yesterday I saw a photo of a
fairly routine-looking player piano, but with this amazing description:

  "Vacuum hoses were attached to the piano's 88 keys.  Paper
   music rolls, perforated with tiny holes, were fed into the
   piano on spools.  When compressed air was shot through the holes,
   mechanical switches opened, activating the keys, and voila!
   Invisible hands made music."

I don't think anyone has described this particular mechanism before.

The first peculiarity is that vacuum hoses (presumably big ones, like
Electrolux or Hoover vacuum cleaners used) were attached to the keys.
The vacuum hoses must have been attached to the tops of the keys with
hot hide glue, since there wouldn't be enough room below.  It probably
would have made the piano difficult to play with any hands other than
the invisible ones mentioned.

Apparently, the rolls did not pass over a tracker bar.  Instead, they
were "fed into the piano on spools."  I am unaware of any other player
piano that ate piano rolls, but it must have been good for the roll
business.  I assume that piano was fed from the sides or back, since
the front would have been pretty cluttered with all those vacuum hoses.
I also don't know how often the owner had to clean out the rolls that
the piano consumed.  Maybe it had a primitive digestive system that
produced piano roll excreta,  utilizing silverfish  just as our
digestive tracts employ bacteria.

And then, of course, "compressed air was shot through the holes."  My
guess is that the piano used a separate, external tank of compressed
air,  since the inside of the piano would have already been full of
vacuum hoses, mechanical switches, devoured piano rolls and such.
I don't know whether the owner needed an air compressor on premises
or if tanks of compressed air were delivered at dawn by uniformed
compressed- airmen, much like milkmen and icemen.  Or maybe the pedals
operated a small compressor.

It must have been astonishing to see this baby operating at full tilt:

  vacuum hoses sucking,
  spools of rolls a-feeding,
  compressed air a-shooting,
  mechanical switches opening,
  keys activating,
  invisible hands a-playing,
  six geese a-laying . . .

Anyway, my l922 Waltham Standard Action Player and PianoDisc/Young
Chang Grand-Piano-Shaped-Object seem pretty insipid by comparison.

Happy Holidays --

Mike Ryan
Milwaukee WI

 [ "... and a tracker-bar pump underneath the tree !"  ;)  -- Robbie