I hit upon an idea, even though it may be considered silly by some.

Many people tell me that a solenoid player piano is not as much fun to
play as in a pedal player piano, because there is no interaction with
the operator.  What if a foot pump, like from an Aeolian or Gulbransen,
could be built to interact on the solenoid type player in the exact
same way as a pneumatic piano, except send it's commands via MIDI?

It would be fairly easy to do this.  First, a variable resistor could
be installed on the bellows; this device would send loudness commands
to the MIDI processor, the level depending upon the position of the
pneumatic.  A clock generator could also be installed, so when the
operator stops pumping, the music stops, much in the same manner as
a pneumatic stack.  To really fine tune the effect, the clock could
be programmed to slow down and then stop (referred to as "coasting"
in a tight player.)

Since it would be constructed from a old player pump, a full compliment
of pneumatic controls could also be used, like hammer rail lift, a
"honky tonk" attachment, and a sustain pedal operated by MIDI valves.

Daydreaming again

Andy Taylor
Tempola Music Rolls