explanation(s), please

[Ron Nossaman]

> It doesn't sound typical, but is the block moving/rocking? 

That's at the widest part of the block. How could a block 6+" 
wide rock enough, especially affecting just 5 unisons at the 
treble strut, to do that? I've read a lot about rocking blocks 
through the years, but the geometry doesn't typically fit the 
description.


Are there gaps between the frame and the block?

Same question. With the block width at that spot, how could it 
spring in enough to so drastically affect those five notes and 
nothing else around them? And why hasn't it quietly done it 
all along instead of just now, with a BANG?

If it is a pinblock problem, maybe a sudden internal 
delamination and split is the culprit, in which case the piano 
is still kaput.

Ron N