String breakage

[Mike Imbler]

Ken & list;

I understand your question, and I may have been too brief in my explanation.
Acceleration exists only in the presence of a force (f=ma, force = mass
times acceleration). Once the hammer has left the action all force is
predetermined
i.e. friction and wind resistance &  gravity. Therefore, the pianist could not
influence it.  Jim has presented an interesting study that the dynamics of
the keyboard "thunk" combines with the piano's tone to create the perceived
difference in tone due to technique.  This makes intuitive sense to me; but
I do doubt that it would influence tone to the degree that people recognize
a pianist's tone from a recording as many claim.  I think that is probably
more due to a pianist style and technique independent of tone production
(i.e. I don't think the oscilloscope would detect it!)

                                          Regards,  Mike
At 11:33 AM 4/12/97 +0000, you wrote:
>
>	Mike and all,
>
>	I, too, have been curious as to the scientific explanation of the
>different sounds which different pianists can produce. I have listened to
>pianists whose touch made the piano sound out of tune (not because of
>excessive volume) and then the next pianist sat down to the piano and made
>it sound beautifully in tune.
>	I have wondered if the differences could be accounted for by the
>fact that the hammer may be accelerating in speed as it strikes the string
>or decelerating in it speed. Perhaps this possibility, along with widely
>differing rates of acceleration and deceleration may provide the answer.
>
>On Sat, 12 Apr 1997, Mike Imbler wrote:
>
>>
>> Kuang wrote
>> >	Right now I'm trying to figure out why alot of pianists believe a
>> >note played at same dynamic can have different tone quality depends on how
>> >you play it (there might be a reason behind it).  Can this be easily
>> >explained?  Or is this a wives' tale?  Can someone with a very good
>> >understanding of action/mechanism express their opinions?  Are modern
>> >pianos designed so pianists can change the tone quality while playing
>> >(e.g. during a performance) as much as they want without
>> >voicing/regulating?  Is there a way a technician can optimize a piano to
>> >do this?
>>
>> As a mechanical engineer by trade (piano student by avocation) I've been
>> interested
>> in the belief you express above.  It is widely believed, but can be
logically
>> disproved (unless someone on the list finds a flaw in my argument!).  The
>> pianist
>> determines the velocity of the hammer by how he presses the key.  He could
>> arrive
>> at the same velocity by pressing the key in a variety of ways i.e. hard for
>> a short distance, medium throughout the active range, hard at the end of the
>> stroke, etc.
>> However, when the hammer has that velocity and is no longer in contact
with the
>> forcing function, elementary physics says it will react the same way from
>> that point
>> forward no matter how it was accelerated to that velocity.  The piano action
>> is no longer in contact with the hammer, and at that point is is affected
>> only by friction and air resistance which the pianist does not control.
>> Therefore, the tone would be identical for all the techniques above that
>> resulted in the same hammer velocity.
>> In other words, on a particular piano, for a particular volume, tone will be
>> the same
>> regardless of the technique used to arrive at that volume.
>>
>> I think that much of "tone" that is attributed to pianists is actually
>> articulation,
>> and probably most greatly noticed is volume weighting within chords or
>> harmony which
>> greatly impacts perceived "tone".
>>
>>                                    Regards,  Mike
>>
>>
>
>