Hammers (long)

[Horace Greeley]

Steve,

At 11:52 PM 12/1/97 -0500, you wrote:
>"Resilience" or compliance is a tricky one to describe, but even harder to
>measure effectivel.

Is there a way to effectively measure it, or, must we project
what we think is going on, based on models developed from
perceptions of phenomena outside the initiating event; e.g.,
measuring differences in relative strength of partials.

One might imagine the placement of (very) tiny
accelerometers within hammers in various sections
of the instrument.  But would they not materially change
the very response they are supposed to measure?

>this is the cause of the fundamental principle of the "piano
>sound". Microscopically it is related to the ease with which the layers of
>fibre can slide over each other as they are compressed...obviously easier
>at first, then progressively harder. Initaial density distribution is
>important, as is the initial distribution of felt layers according to high
>or low pressure, heat or cold etc....as observed by Del. Doping alters
>this sliding relationship and hence the compliance curve. Internal
>friction is another consideration that is observed in hysteresis effects,
>whereby different curves are followed according to relaxation and
>compression...bad doping can make the hysteresis gap too large, causing
>undesirable effects. Last has not been hinted at this time...what I would 
>term resilience failure, the gradual decline in resilience or 
>flattening of compliance curves as the hammer is subjected to repeated 
>cycles of compression and relaxation (= regular playing). Manufacturing 
>technique will probably have a big influence on this lifetime aspect of 
>the hammer...I think a place where doped hammers have the edge.

I think that you've hit on a very important distinction here.  While I
certainly agree that, in the best of all possible worlds, hammers
would spring full-blown from their molds in perfect shape with
perfect resiliance, and all would be well.  As we all experience
daily, however, this is not that place, and hammers are nowhere
close to perfect.  Also, neither are pianos, or the places in which
they are played.

In that context, my main objection to too-hard/too-soft hammers is
that they tend to bring out the sloth in each of us.  On the too-hard
side, we have pianos with more splat than tone.  On the too-soft
side, we have pianos with tone than barely creeps off the end
of the keyboard before falling flaccidly to the floor.

That being said, my personal preference is for the too-soft
variety.  After many years, the reasons remain, carefully
(lacquer) hardened hammers, with reasonable maintenance,
maintain whatever you give them for many years.  I
still, occasionally see instruments set up by either
myself (or people I worked with) 20 to 50 years ago.  Certainly
not in every instance, but in many, the original
basic voicing is still intact.

Further, the softer hammers seem (to me, anyway)
to be more forgiving of scale and stringing kinds of 
problems than harder ones.  This is a long way to go
to say that I agree with Steve that doped hammers
have (something of) an edge.

Lots of good stuff here.  Helps to keep in mind that
what we practice remains an art.

Best.

Horace

P.S. - I've worked with George Winston for nearly
20 years, in studios, and in more concert venues than
I care to think about.  Whether one likes his music
or not is inconsequential.  George is a serious
professional artist who demands from those around
him no more than he asks of himself, the best they
can offer.  He fully understands where the piano,
the technician, and he intersect; who is responsible
for what, and what it is reasonable to expect from a
given situation.  George is a consummate gentleman,
he is strongly committed to arts education, as well as
to a variety of social causes.  His contract rider was 
developed with the input of several technicians, over 
a period of time, as it became clear that that was the
only way him to get consistently prepared instruments.

hg
Horace Greeley

Systems Analyst/Engineer
Controller's Office
Stanford University

email: hgreeley@leland.stanford.edu
voice mail: 650.725.9062
fax: 650.725.8014