Dear MMDr's -- Just a friendly disagreement concerning L. Douglas
Henderson's last entry about the Welte recording process.  Mr.
Henderson states that the travel of a piano key is (in his word)
"_fixed_".  That is incorrect in the literal sense.  (However,
good piano technicians do their best to arrive at that perceived
effect!)

Every piano key in _any_ piano is suspended/held into position by felt.
In "non-playing status" the back part of the key (the lever that it is)
seats on a continuous strip of thick woven felt.  The front part of the
stricken key lands on a thick circular felt punching whilst the center
pivot point "teeter totters" on a comparatively thinner circular
punching of felt.  The point is: felt, is felt, (no matter how finely
and carefully it is produced) and is flexible and pliable, susceptible
to many circumstances.  And mostly under pressure.  Yeah, playing the
keys hard will most definitely compress the felt.  Forte = more key
travel due to compression, Pianissimo = fluffy, more resilient felt
limiting key travel, measured in mere fractions of a 16th of an inch.

The travel of a piano key is no more "fixed" than the circumference of
the tires on your car are "fixed."  Yes, they appear to be uniform and
round but we all know that running over a curb will certainly flatten
out a tire if only momentarily.

The same is true with piano felt.  Under extreme pressure it will
absolutely compress; it is felt and it is this property that gives
the minute touch/response so desired by actual pianists.  Human, not
mechanical, but the mechanical (whatever system it is) is only as good
as the keyboard it's attached to.  (Most upright player mechanisms
wouldn't apply, of course, since they engage the abstracts of the
action and not the actual keys themselves.)  But correct key travel,
level, height, etc., are essential to the operation of a reproducing
grand and would have to absolutely be perfect for the Welte recorder
to even function as it has been described.  All this of course is
predicated upon the properties (such as thickness, firmness, height
etc.) of the felts.

Underneath every felt punching in every single piano you will find
a few, or a stack, of paper, cardboard, even tissue paper punchings.
This is to compensate for the various inconsistency of thickness and
pliability of the felt.  The felt punchings may _appear_ to be
identical and even measure somewhat uniform, but the "give" on each
one can vary quite a bit when you're really splitting hairs.  Hence
the paper/card punchings to compensate for touch, aftertouch, evenness
and leveling of the keyboard.

Therefore;  if the Welte recorder functioned the way that "legend has
it", it most certainly _could_ have achieved it's intended purpose in
my opinion.  That is, since key travel is supposed to be uniform but
is innately variable and cannot possibly be "fixed", it would have had
to have been capable of detecting the difference of key travel (felt
compression) within only a few hundredths or even thousandths of an
inch.  I would imagine that the calibration of such a device would have
taken weeks of trial and error just to find _a_  window of accuracy,
not to mention a precise one, plus being coupled with all the other
machinery that went with it!

That alone is quite a remarkable achievement, but consider this:
due to the lack of storm windows, insulation, and modern heating we
have today, they must have regulated that piano daily in order for the
recorder to register properly.  And the tuning?!  Must've been quite a
lot of piano techs in the neighborhood.

Eric J. Shoemaker

PS.: I hope no one invents consistently stable piano felt or I'll be
playing a Rolmonica in front of a Starbuck's for cash!

 [ I once had to play a nasty little lounge piano with no resilient
 [ felt or other punchings remaining below the front of the keys.
 [ (The balance rail punchings were missing, too, so I guess that's
 [ why the action operated okay otherwise.)  My fingers and hands
 [ ached horribly after four hours playing.  -- Robbie