Spencer Chase suggests in his "tuning a player piano" note [120310
MMDigest], that nothing can be done at the keyboard that can damage
a piano that is not already in sad shape.  I beg to differ.  On one
occasion, while I observed, a kid was smacking the keyboard with his
fist.  A very short time thereafter, two notes no longer functioned.
When we opened the top and looked in, two hammers could be seen laying
where they fell after they broke off.

Now, it may be that some will say, "This was not a well-built piano;"
I don't know.  Still, I won't let anyone operate the keyboard on my
piano in any manner other than what it looks like for a piano player
to play the piano, and I recommend that standard to others.  Piano
keyboards are not generally built to withstand fist-swinging.

Lee Rothrock