[CAUT] S & S D rest cushions

[Fred Sturm]

On Aug 17, 2009, at 12:55 PM, Susan Kline wrote:

> EXACTLY. Two notes right after each other, played pretty hard and  
> staccato.
> (What I described as "ba-DING".) And the rest of the checking and  
> repetition
> seemed just fine, all the rules were followed, etc. However, when I
> encountered it, the rest felt was not far from the shank, just a  
> normal
> distance. I've encountered this on two pianos -- the first was the  
> teflon
> rebuild, and needed repinning, nothing else would do. The second was
> nearly right, but a note or two would jam in the two-note situation.


	Actually, rather than one scenario, I think there is a range of  
things that ought to be called a CAF syndrome, probably with a range  
of details that could be analyzed as causes. One element that is often  
involved is keystrokes which don't activate the back check: either the  
stroke is so fast (and the key is released instantly) that the check  
has got out of the way when the hammer rebounds, or there is a partial  
key depression where the check never gets high enough (this is usually  
on rapid repetition, where fingers stroke the top of the key and slip  
off the front to get out of the way for the next finger). Both of  
these are actually fairly common. So if we are relying on what we have  
done to the backcheck and tail, we may be missing the boat. And here a  
possible rebound off close cushion felt may be absolutely key to  
making it work. But this is speculation, since it all happens so fast  
and is so complex that we don't really know.
Regards,
Fred Sturm
University of New Mexico
fssturm at unm.edu