Hi All,  I'm not sure how many people will be interested in seeing
this, but I shot a couple of short videos that show a simple invention
of mine that I use for testing the valves and pouches in the modern
Universal player piano.  The videos are located at

  http://www.youtube.com/watch?v=kwD-kTbLmgg 
  http://www.youtube.com/watch?v=0kcZrPFB3RI 

I was a bit surprised to find out how fast the valves and pneumatics
could actually cycle with this simple device -- around 200 Hz!

Musically,
John A Tuttle
Player-Care.com
Brick, NJ, 08724