I am in full agreement with David Porritt. I have thoroughly enjoyed, thought deeply about, saved for further study, and deleted many of these convoluted discussions (especially this one and the "what really makes a piano go out of tune?") Thank you all for your time.
<br>Nancy Salmon<br>Frostburg State University<br><br><div><span class="gmail_quote">On 9/4/07, <b class="gmail_sendername">Porritt, David</b> <<a href="mailto:dporritt@mail.smu.edu">dporritt@mail.smu.edu</a>> wrote:
</span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div link="blue" vlink="blue" style="" lang="EN-US">
<div>
<p><span style="color: rgb(31, 73, 125);">Jim:</span></p>
<p><span style="color: rgb(31, 73, 125);"> </span></p>
<p><span style="color: rgb(31, 73, 125);">Please don't take this
entirely off-list. There are some of us who have nothing to contribute in
that we have no experience with this wire, but our interest is high and
curiosity even higher. The last I knew the PTG server is capable of quite
a bit more traffic before it gets "clogged". While some seem
to have an irritation gene that gets activated by certain threads, most of us
have pretty nimble delete-key-fingers capable of deftly deleting posts that don't
interest us.</span></p>
<p><span style="color: rgb(31, 73, 125);"> </span></p>
<p><span style="color: rgb(31, 73, 125);">dave</span></p>
<p><span style="color: rgb(31, 73, 125);"> </span></p>
<div>
<p><span style="color: rgb(31, 73, 125);">_______________________</span></p><span class="q">
<p><span style="color: rgb(31, 73, 125);">David M. Porritt, RPT</span></p>
<p><span style="color: rgb(31, 73, 125);"><a href="mailto:dporritt@smu.edu" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">dporritt@smu.edu</a></span></p>
</span></div>
<p><span style="color: rgb(31, 73, 125);"> </span></p>
<div>
<div style="border-style: solid none none; border-color: rgb(181, 196, 223) -moz-use-text-color -moz-use-text-color; border-width: 1pt medium medium; padding: 3pt 0in 0in;">
<p><b><span style="font-size: 10pt;">From:</span></b><span style="font-size: 10pt;"> <a href="mailto:caut-bounces@ptg.org" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">caut-bounces@ptg.org</a>
[mailto:<a href="mailto:caut-bounces@ptg.org" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">caut-bounces@ptg.org</a>] <b>On Behalf Of </b>Jim Busby<br>
<b>Sent:</b> Tuesday, September 04, 2007 11:35 AM<span class="q"><br>
<b>To:</b> College and University Technicians<br></span>
<b>Subject:</b> [CAUT] FW: Scientific study - Stainless wire (Help!)</span></p>
</div>
</div><div><span class="e" id="q_114d18333eaa167a_5">
<p> </p>
<p><span style="font-size: 10pt; color: navy;">List,</span></p>
<p><span style="font-size: 10pt; color: navy;"> </span></p>
<p><span style="font-size: 10pt; color: navy;">No offense is meant to anyone by naming several below as
"thinkers". What I meant to say is that those listed have actively
written lengthy posts of their thoughts on this study. I will move this thread
off CAUT to private posts mostly to them rather than clog the list. Sounds
really bad, the way I worded that. Sorry. (Put foot firmly in mouth…)</span></p>
<p><span style="font-size: 10pt; color: navy;"> </span></p>
<p><span style="font-size: 10pt; color: navy;">Regards,</span></p>
<p><span style="font-size: 10pt; color: navy;">Jim</span></p>
<p><span style="font-size: 10pt; color: navy;"> </span></p>
<div>
<div style="text-align: center;" align="center">
<hr align="center" size="2" width="100%">
</div>
<p><b><span style="font-size: 10pt;">From:</span></b><span style="font-size: 10pt;"> Jim Busby <br>
<b>Sent:</b> Tuesday, September 04, 2007 10:26 AM<br>
<b>To:</b> 'College and University Technicians'<br>
<b>Subject:</b> RE: [CAUT] Scientific study - Stainless wire (Help!)</span></p>
</div>
<p> </p>
<p><span style="font-size: 10pt; color: navy;">Thanks, yet again Fred,</span></p>
<p><span style="font-size: 10pt; color: navy;"> </span></p>
<p><span style="font-size: 10pt; color: navy;">Very detailed observations! About thumpers, it seems to me that the
real issue in this study would be;</span></p>
<ol style="margin-top: 0in;" start="1" type="1">
<li style="color: navy;"><span style="font-size: 10pt;">Ability to
reproduce the exact stroke w/o variation</span></li>
<li style="color: navy;"><span style="font-size: 10pt;">Elimination of
"the human element"</span></li>
</ol>
<p><span style="font-size: 10pt; color: navy;"> </span></p>
<p><span style="font-size: 10pt; color: navy;">In this regard the Disklavier would be ideal because according to
Yamaha it can reproduce what the human plays to a 100 point scale. IOW if you
hit the velocity at 69 (out of 100 possible), the "machine" will
reproduce it at volume 69 time and time again, as long as the machine has been
calibrated and not changed during the test time. Of course this precludes human
error upon reproduction on that piano. </span></p>
<p><span style="font-size: 10pt; color: navy;"> </span></p>
<p><span style="font-size: 10pt; color: navy;">All the mechanical devices seem moot as to the validity of the
testing as long as it meets the criteria above. Correct?? At least as far as
the testing of wire, sound, and acoustic considerations are concerned. But hey,
you're the braniac here! I'm the farmer who uses bailing wire and
duct tape… </span></p>
<p><span style="font-size: 10pt; color: navy;"> </span></p>
<p><span style="font-size: 10pt; color: navy;">Whatever method these guys use will, of course, be posted so it can
be critiqued. I will pass this along to them. It is still open as to what they
want to test. Hopefully we will have that narrowed down this week and the
testing process can proceed. I'll definitely keep you posted. You, Jim
Ellis, Ric B and Juan seem to be the most active "thinkers" in our
pool of technicians (ON THIS TOPIC!!) and I'm posting privately to you
more than CAUT. Jim is especially active in this study. Ric may bring a
different side to the table with his European influence, and he seems to like
to crunch numbers, and Juan, of course, has already done a battery of
tests.</span></p>
<p><span style="font-size: 10pt; color: navy;"> </span></p>
<p><span style="font-size: 10pt; color: navy;">Regards,</span></p>
<p><span style="font-size: 10pt; color: navy;">Jim </span></p>
<p><span style="font-size: 10pt; color: navy;"> </span></p>
<div>
<div style="text-align: center;" align="center">
<hr align="center" size="2" width="100%">
</div>
<p><b><span style="font-size: 10pt;">From:</span></b><span style="font-size: 10pt;">
<a href="mailto:caut-bounces@ptg.org" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">caut-bounces@ptg.org</a> [mailto:<a href="mailto:caut-bounces@ptg.org" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">
caut-bounces@ptg.org</a>] <b>On Behalf Of </b>Fred
Sturm<br>
<b>Sent:</b> Tuesday, September 04, 2007 8:16 AM<br>
<b>To:</b> College and University Technicians<br>
<b>Subject:</b> Re: [CAUT] Scientific study - Stainless wire (Help!)</span></p>
</div>
<p> </p>
<div>
<div>
<p>On Aug 28, 2007, at 8:29 PM, Jim Busby wrote:</p>
</div>
<p style="margin-bottom: 12pt;"> </p>
<p><span><span style="font-size: 10pt; color: navy;">We did devise a thumper, but
I'm wondering is a Disklavier would be the way to go. Consistency was
definitely an issue with our meager spectrum studies. I'm really hoping
that these "science professors" will take the ball and run with it.
That is what they do.</span></span></p>
</div>
<p> </p>
<div>
<p>Hi Jim,</p>
</div>
<div>
<p><span>
</span>Let me give just a few quick thoughts about "thumpers" and
other devises for activating a key, to give your physicists an idea of some of
the problems involved. The tuning test thumper drops a weight from above the
key. There is a free fall of 6 inches or so before the weight hits the keytop.
It has now achieved a certain velocity, and is still accelerating with gravity
(a simple calculation can give the specifics). So far so good.</p>
</div>
<div>
<p><span>
</span>Now comes the moment of impact. The key is in a state of inertia,
as is the whole key/action assembly. During impact, there is a period where the
colliding bodies "bounce against each other." The weight slows
suddenly, or possibly stops falling altogether or bounces upward (we'd need
some high speed videography to know for sure what happens). The keytop absorbs
this enormous force, which has impacted it suddenly.</p>
</div>
<div>
<p><span>
</span>This scenario is far different in many ways from the way a pianist plays
a key. If he/she plays the key with a great deal of force, slamming down from
above the key (more or less like the falling weight), the difference is that
the mass of the body behind the finger will push all the way through the
keystroke with only a minimal "rebound" effect. And, as we have seen
in various high speed films, the front of the key will hit bottom before the
hammer begins to move (flex and compression allows this). But this is an
unusual piano technique. </p>
</div>
<div>
<p><span>
</span>Far more common is simple pressing of the key, starting with the finger
contacting the keytop, and accelerating the key. This technique can be used to
create a full range of the available volume of the piano (not counting
percussive sounds from the key crashing into the keyframe/keybed, in that
slamming action described above). And I think that any study involving tonal
output of a piano ought to be based as nearly as possible on normal key
activation. The problem with using a real live pianist is that you can't be
sure of exact repeatability, and being exact is tremendously important in this
area. Joggle a mike, play a little louder or softer, and the spectrum and even
measured pitch will change.</p>
</div>
<div>
<p><span>
</span>Askenfeld (did I get that right? the guy in Sweden who put together the
5 Lectures in PIano Acoustics) said in his lecture that he used a pendulum to
activate a key. This makes some sense, as its velocity at impact can be
controlled by how far it is allowed to swing (position before letting it go),
and bounce is minimized because of the oblique angle with which it strikes the
key. But it is still a rather artificial setup: a body in motion suddenly
impacts the key, and the arc of movement means that the downward movement of
the pendulum weight is probably decelerating (a pendulum weight moves downward
most when it is at the same level as the pivot point, and it moves downward
less and less as it approaches the bottom. Even though the weight is
accelerating to that point, the geometry is such that its downward motion is
becoming less and less). So I'm not convinced a pendulum is a good substitute
for a finger.</p>
</div>
<div>
<p><span>
</span>I guess the disklavier/pianodisc/pianomation systems with their
controlled solenoids do a reasonable job. I haven't really fooled with them
enough to have an opinion. It's going to be a sudden electromagnetic charge of
a controlled amplitude creating a an electromagnetic attraction of a
corresponding force. Does this replicate what a finger does? I think a finger
has more possibilities, in terms of how much acceleration it imparts to the key
in any given portion of the key travel. (I have puzzled a good deal about how
it is possible to make one finger's note stand out when playing a chord.
Somehow that hammer had to be given more velocity. But it all happens so fast,
and is so hidden in psychology, that it is hard to get a handle on it).</p>
</div>
<div>
<p><span>
</span>Anyway, I will again say that I think a mechanical devise, with a system
of accelerating levers activated by a weight, and with the mass and placement
(leverage advantage) of the weight being variable, would be a great
contribution to study of any number of things to do with pianos.</p>
<div>
<div>
<p>Regards,</p>
</div>
<div>
<p>Fred Sturm</p>
</div>
<div>
<p>University of New Mexico</p>
</div>
<div>
<p><a href="mailto:fssturm@unm.edu" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">fssturm@unm.edu</a></p>
</div>
<div>
<p> </p>
</div>
</div>
<p> </p>
</div>
<div>
<p> </p>
</div>
</span></div></div>
</div>
</blockquote></div><br>