S&S: key-frame return spring

[thepianoarts]

Hi Mark,

I am sure you have located the source correctly, but after much trial and
error, mostly error, I now treat the back verticle edge of the key frame
where it could touch the dags, etc. Sanding would work too. It is a tough
one (noise) to trace, but common.

Just courious...  
Was the spring singing, or the wood frame resonating? (How about polishing
the spring?)

Dan Reed
Dallas