Many years ago I contracted to record a few of my 88-note rolls for a
record producer, using my Aeolian Themodist pumper.  Since the piano
was -- as usual -- in need of further rebuilding, I chose to fit an
electric motor in place of the airmotor, thus my foot-pumping energy
could go entirely into the music.

I could not find a suitably quiet motor, except for the motor in my
Ampico B piano, which I didn't want to dismantle.  So I put the
quietest cheap gearmotor I had (Barber-Coleman) _underneath the
keyboard_, down with the foot pump and reserve pneumatics.  I used an
automobile speedometer cable to connect the gearmotor shaft to the
"fast" shaft in the spoolbox above the keyboard.

It served my purpose quite well.  Because the motor was lightly loaded
during playing, the voltage at the motor armature was in close
porportion to the motor speed, and a simple voltmeter displayed the
relative "Tempo".  The power was from a continuously-variable,
regulated d.c. power supply, which fortunately could supply enough
current for rewinding the roll.

For the audio recording I moved the piano into the center of the room,
and I suspended the pair of microphones from the ceiling, to point at
the inside of the piano adjacent to the spoolbox.  Without the music
playing only a little noise from the spoolbox transmission could be
heard.  It was necessary to set the airmotor governor to a slow speed
(Tempo 30?) so that the reserve could "bleed off" pressure and thus
respond normally to accents.

After the "recording session" I dismantled the system and restored the
piano to it's normal configuration.  It's more fun that way!

Robbie Rhodes