Thanks to all who are contributing to the discussion on the
physical actions involved in tuning a piano.  Those who tune, but are
not themselves experienced pianists, should understand that a lot more
goes into a large, resonant piano sound than "hitting the keys hard."
I am reminded of the liner notes of the Columbia set "Nyiregyhazi Plays
Liszt," in which a technician describes hitting the keyboard with his
fists in an effort to set recording levels before the session, only to
discover that the pianist produced a far greater sound with little
effort.

What progress I have made in fortissimo playing has been achieved by
a "cracking the whip" motion, in which the arm is imagined to be an
outer extension of the key lever, and the energy is thrown into the
keyboard through a sort of wave.  One person can appear to be hitting
the piano harder than another person, and yet be producing a shallower
sound.

Jurgen Goering mentioned Franz Mohr (Chief Concert Technician for
Steinway from 1968 to 1992) as perhaps not striking forcefully while
tuning.  I love Mohr's book "My Life With The Great Pianists," and
while he does not specifically address that point in his chapter
"Tuning a Piano," he does say this:

  "It is very important that the concert tuner tune very solidly.
  By this I mean that the piano for a concert must be able to
  withstand a real beating. ... We have to tune in such a way that
  after the concert is over, the piano will still be in tune, in as
  fine a condition as it was before the concert.  That can be
  achieved.  [author's emphasis]  I always say that it is difficult
  to find a tuner who tunes on a high level of workmanship, but that
  it is even more difficult to find among those who tune very well,
  one who also tunes solidly, so solid that that the piano can really
  take a beating in the concert and still be in tune.  One can only
  become a solid tuner by working on it constantly, and by never
  losing sight of the fact that this piano is going to be used for
  a concert.  No tuner should ever take the tuning hammer off of the
  pin he or she is working on without being absolutely sure that this
  note, this string, will withstand the strongest beating, and will
  not budge in any way.  This takes time!"

I would think these words also could apply to the beating a player
piano takes.

James Neher
Pennsylvania