test blows

[Bill Ballard]

At 10:01 AM -0700 8/19/03, David Love wrote:
>As a general rule, if unisons go out it's your technique, if the intervals
>go out while the unisons stay solid, it's the environment.  There are, of
>course, always mitigating factors.

I used to believe that if the board moved with the ambient RH, the 
balance of tensions at the front side of the speaking length would be 
altered, pushing the unisons to the edge of stability. (The balance 
at the bridge end of the speaking length was not affected because 
both segments were tied to the board at he bridge.)

Then, in 1995, Doug Kirkwood and I calculated the friction barrier 
which the capo presents to C5 on a Steinway B, as well as the maximum 
tension spike in the speaking length caused by my hardest tension 
blow. The friction barrier (as inferred from the side elevation of 
the string path....ie. between the tuning pin and front duplex, so 
many inches length combined with so many inches vertical rise, etc.) 
was in the neighborhood of 20.4#, if memory serves (I can't find my 
notes). The maximum served displacement at C5's strike point was 
0.049", which translated to somewhere around 3 oz. Apparently, a test 
blow could barely muster 1% of the friction barrier at the capo.

What is not known is the size of the friction barrier presented by 
the bridge. I'd assume that test blow applies the same 3 oz. tug in 
both directions. If it's at the bridge where all these unisons get 
spoiled, then the barrier there has it be considerably less. However, 
if it is less (especially if it's under a pound, where the test blow 
could actually knock something loose), then the likelihood of tension 
imbalances across the bridges (the source for smudged or mashed 
unisons) would also be reduced.

So I came away from that, relieved that a karate chop test blow (as 
demonstrated by Ludwig Tomescu during the week I spent at Steinway's 
basement in '88) was beside the point of stable tunings. (By stable, 
I assuming we mean, short term, in particular through the evening on 
concerto night. Long term brings climate in as a player, and there is 
nothing our hammer technique can do about that.)

It's my belief (IMHO) that tuning stability is in the right hand 
(hand on the hammer), not the left. I judge stability with the simple 
"bump-up-bump-down" test. If I gently bump the hammer in either 
direction and if the temporary change in pitch is the same in both 
directions, then I judge that, with the speaking length pitch moving 
identically with the same size bump in both directions, both the pin 
and the string are in the middle on the "stable zone". (Not to 
further complicate things, but frequently the string friction barrier 
(going over the string rest, the front duplex and the capo/aggraphe) 
can be high enough that considerable tension imbalances can exist in 
the string path and a test blow still won't knock them loose.)

I believe that it's entirely possible to do a stable tuning, giving 
the keys a blow no harder than what's possible with the finger 
touching the key at all times. I haven't tried it yet, but I'm 
willing to bet a sasparilla in it.

At 2:57 AM -0400 8/19/03, Don wrote:
>Yes some coils need to be lifted--but I do that with an
>impact type of coil lifter--so I'm still tapping--just upwards.

I remember Willard Sims of Baldwin (at either the Philly National in 
the early 80s, or the Cincinnati in '78), saying that the factory was 
interested in just how necessary tight tuning pin coils were for 
tuning stability, so they strung a piano up with sloppy coils and 
sent it on down the line, looking for comments on tuning stability. 
It apparently was no less stable than any of the pianos with tight 
coils.

Bill Ballard RPT
NH Chapter, P.T.G.

".......true more in general than specifically"
     ...........Lenny Bruce, spoofing a radio discussion of the Hebrew 
roots of Calypso music
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