Voicing and Inharmonicity

[Jim]

There are those who have measured differences in inharmonicity as a
result of voicing.  Whether or not we understand just why is not germaine
to the issue. There are also some who have measured the difference in
pitch produced by 3 identical strings individually as compared to the
3 strings in unison. Whether or not we can explain it is inconsequential.
It is just there.

My reasons for the inharmonicity differences that are measured due only
to voicing changes go like this.  We know that piano string sounds are
transient. Energy vaccilates between several partials as the piano sound
decays.  Sonographs show this undulating effect. As one partial increases
in amplitude (and hence its tension increase at that freq.) the pitch of
that partial changes. I know, that this last statement sounds like
heresy.  We already know for sure that as a tone decays, the amplitude
decreases, the tension decreases, and the pitch decreases, so, you can
apply these same principles to individual partials.  When certain deep
shoulder needling takes place, the lower partials can be made to grow
and the sustain increases.  One can argue that the overall tension does
not increase, however, as pertains to the lower partials which after
voicing as above, there is greater amplitude hence greater tension distri-
bution applied to those lower partials and robbed from other more
obnoxious partials.

Chris Robinson is one who has measured differences in inharmonicity due
to voicing.  Others also have whose names do not come to mind at this
time.

Jim Coleman, Sr.