Cross-country piano move

[Randy Potter]

Regarding the pitch change from placing a piano on a dolly after tuning,
or tuning it while on a dolly and then taking it off -

I suspect, however, that if you checked the piano you would have found a
wide variance throughout the whole piano, not just across the bass-tenor
break.
Bill Spurlock showed me this, and I have done it myself while teaching
classes also (and in a few client's homes, too, when it was appropriate)
-
1)  Tune an octave right in the treble, something like F69-F81.
2)  Play the octave, and listen its proper, clean sound.
3)  Raise your foot, so your knee lifts the treble end of the piano under
the keyboard near the treble leg . . . and
4)  Listen to the sour octave, as the frame twists and causes a tension
change in the strings. So much tension change in the top note that the
octave starts to beat it self up!
5)  Relax your leg, and let the keyboard return to its original position
- but be sure to be playing the octave when you do, because you will hear
the disharmony change to the octave sound you had before you did this.

This makes sense, since the piano was designed to have its frame members
supported by its four corners (at the casters). Three, of course, for
grands. When we put it on a dolly - which removes the support (tension)
from the four corners and adds tension at the center of the skeleton &
frame, it makes sense that pitch will change.
Amazingly enough, removing the dolly (or your leg, as in the example,
above) will return the tension (pitch) to about what it was before.

This is why moving a piano a short distance (across the room, or maybe
across town), properly, using the correct equipment and techniques
(something we expect of movers who are getting paid money, rather than
the friends who are helping for their share of a case of beer when the
job is complete) - this is why moving a piano a short distance, properly,
causes very little disturbance to the tuning of a piano that is up to
pitch and in tune.
(Of course, most pianos are not "up to pitch and in tune" when they are
moved, so they "need to be tuned" after the move. In most cases, we piano
technicians know, they "needed" to be tuned before they were moved - and
should have been tuned even if they were not tuned. But we also know that
in many cases they would not have been tuned had they not been moved.

Do I tell all of this to my clients, so they will be well-informed? No.
Why not? Because most of them do not care. And most of them do not want
to hear it. And most of them would not understand it if we tried to
explain it. Heck, many piano technicians do not understand this, either.
In fact, I am not sure that I *really* understand it myself. I know a
little bit about it, and I would not be surprised to find that someone
else reading this will - kindly, I hope - point out where my knowledge
ends and surmising began. As my dad says "I don't understand all I know
about this".

But, perhaps, this helps explain some of why this phenomenon happens.

Randy Potter, R.P.T.



Randy Potter, R.P.T.
Randy Potter School of Piano Technology
"Training Competent Piano Technicians for the 21st Century"
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