[CAUT] Some like it Hot/Some like it Cold!

[Fred Sturm]

On May 22, 2008, at 10:37 AM, Jim Busby wrote:

> The Crescendo punchings don’t compress as much so you get a firm  
> felling of the bottom of the key and exactly where it is. To my  
> limited understanding and experience this is why it “works better”.  
> I just know what the pianists say. As far as the tone goes, there is  
> a difference. You can play with it yourself. (Ed Foote’s post.)
	A couple thoughts about the Crescendo punchings, which I have used a  
bit, but not enough to have really firm opinions on them. First, they  
don't feel as hard as you might think from description. They are  
hammer felt, but not as hard as what is used for hammers. At any rate,  
they feel like they compress more than what we are sold as scrap  
hammer felt. And they are made with undersized holes, so that the  
front rail pin seems to "spring" them when they go on, making them a  
bit thicker.
	About how they could affect tone, well, remember that even though we  
think that by the time the key hits bottom, the hammer is no longer  
being propelled, it really isn't so, at least on relatively hard  
blows. High speed videography shows that for a fairly wide dynamic  
range (forte and more) letoff occurs after bottoming of the key. For  
fortississimo blows, the hammer barely moves before the key bottoms,  
at least with some keys (some designs stiffen keys more than others).  
So there could very well be feedback somehow "through the key to the  
hammer." I think I'd guess that a woven punching would have more of a  
deadening/damping impact on the key, while the felted one might  
reflect some energy back from the front of the key through the key  
toward the capstan. Speculation, but a possible mechanism. I'm  
thinking that maybe it acts just like hammers, in having that "non- 
linear hardening" effect, which would make for a variance depending on  
strength of blow in a curve, which might transfer to various elements  
of tone. And I'm not so sure that keybed vibration doesn't have a  
musical function along with the "noise" factor, in vibrating along  
with the whole rim and soundboard assembly, amplifying the energy  
output in some way.
	So there could be something more happening than just a change of the  
impact noise of key on keybed/keyframe.

Regards,
Fred Sturm
University of New Mexico
fssturm at unm.edu


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