<blockquote style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;" class="gmail_quote">Since when was Craig Brougher a "frustrated physicist"?!  He's just a vocal mender of player pianos. </blockquote> My apologies. The way it read and where it was posted led me astray. Does anyone know of any professional scientists who have something to say on this? (BESIDES the two references that were posted on the other thread that were quite old, or a bit vague) <blockquote style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;" class="gmail_quote">When plucked about 24 hours later a fall in the pitch of the note of 4 or 5 cents was noted. 48 hours later the note is 9 or 10 cents flat. </blockquote> This was the tuning pin to tuning pin in the piano leg, right? The clear flaws I see that keep this experiment from saying anything meaningful about string stretching is that the factors of coil settling and wood crushing are completely unmitigated. <blockquote style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;" class="gmail_quote"> There is approximately 400 cents worth of slack in the coil, after being brought up to pitch and pounded for a while.  I don't know if it should be called stretching for this slack to gradually unwind, but if the coil is not squeezed tightly, most of this slack will come out over the first year or two. </blockquote> Granted, this sounds reasonable, but why should such tightening of the slack in the coil happen slowly? What is the physical mechanism that causes this type of pitch drop to be time release? Kurt