I went on a service call with my friend who is really the tech.  The
piano was an upright Blüthner, made in Germany in 1913; a big decal
on the key cover says Hupfeld player.  We can't figure which Hupfeld
system it is.  It is foot pumped, no rubber tubing.  The tracker bar
has two sets of holes: horizontal slits for the 65-note rolls, regular
square holes for the 88s, marked 65 and 88.

A lever at the top of the spool box unlocks the tracker bar -- pull it
out, flip it over and reinsert for either 65 or 88.  It has tracking
only for 88-note as tracking engages a fork in the tracker bar when
in 88-note position.  The tracker bar is a lightweight silver colored
metal -- aluminum?  It is about 4" deep, sort of a manifold and connects
to a "plate" at the back faced with white leather.

Below the keybed is the player stack and a narrow, horizontal pump
with "stuff" in front of it, everything held in with wing nuts.  I'm
assuming the "stuff" is crescendo expression?  The control box flips up
and has Bass and Treble solo levers, a large round button for pedal and
a lever must be for Tempo (a celluloid label with all printing gone).
I cannot figure where Play-Reroll is.  Nothing has ever been touched.
I played a few notes; the striker cloth felt like new, the rest of
cloth felt old but not really brittle.

The piano was bought in England when the owners lived there and was
shipped here when they came back.  They have boxes of various Hupfeld
rolls, some large ones and some Animatic ones.  The owner just wanted
it tuned for now; she says her deceased husband used to play it.
I hope we get to go back.

Jay Merrill, in Indiana

 [ See and hear Blüthner Hupfeld Solophonola pianos performing at
 [ http://www.youtube.com/watch?v=JwKX6R2gXxA (QRS),
 [ http://www.youtube.com/watch?v=q90XtVQmlX8 (Animatic) and
 [ http://www.youtube.com/watch?v=QIPBlkNb15U (QRS).  -- Robbie