Strictly technical

[Delwin D Fandrich]

Ricard de La Rosa wrote:

> The question about the bounding piano on New York Streets had to do with the
> fact that the duplex section of the speaking lengths do get out of tune.  How do
> they get so out of tune after thay have been put "in tune"?  It seems that they
> are jarred sometimes (often in NY) in transit.  I have seen a piano jump up off
> the floor of a truck (before being sedated again) about 6" parallel to the floor
> and slam down with full force after moving truck hit a huge NY type pot hole.
> That type of force, slamming, and banging as it does, can and will move just
> about anything....including a sound board either up and away or down and away or
> sideways and away from the bridge and its pins, etc.  Therefore, in that
> microsecond, who is to say the aliquots do not also move?

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Ricard

It is unlikely that the aliquot segments move even when subjected to the trauma of a
NY pothole.  They are held quite firmly in place by the downforce of the strings.
However . . . it is probable that the plate itself sifts around somewhat.  These
things make up a substantial portion of the pianos weight.  They are held in place
with a mechanism intended to hold them down against the rim/soundboard assembly.
Not much thought is given to withstanding side stresses.  We've repaired several
pianos in which the plates had been shifted enough to cause technical problems.  It
is quite likely that many plates shift around enough to nicely put a piano out of
tune.  It doesn't take much plate movement to accomplish that.

Del