At http://science.discovery.com/videos/how-its-made-player-pianos.html 
is a short video clip (about 100 seconds) filmed at QRS Music Rolls
in Buffalo, New York.

The restored 1912 Melville Clark pneumatic recording piano system
is shown in use while it registers a live recording.  (The modern
laptop computer sitting atop the piano above the keyboard displays
an image of the sheet music to the pianist.)

Then the big QRS perforator is shown, with a rack of solenoid valves
controlled by a vintage Apple IIe computer with dual 5.25" floppy
drives.  Notice the screwdriver and needle-nose pliers on the table
with the computer, possibly used to adjust the long wires that
connect the pneumatics to the sliding interposers in the perforator.

The complete video sequence will be broadcast on the Science Channel
at 12 midnight 9 May 2009 as a part of "How It's Made 6 - Episode 3",
according to the schedule offered at
http://science.discovery.com/tv-schedules/daily.html?date=20090509.129 

Thanks to Mike Walter for this tip.

Robbie Rhodes, MMD