<HTML><BODY style="word-wrap: break-word; -khtml-nbsp-mode: space; -khtml-line-break: after-white-space; "><DIV><DIV>On May 3, 2007, at 11:00 AM, RicB wrote:</DIV><BR class="Apple-interchange-newline"><BLOCKQUOTE type="cite"><P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">Hi Fred.</FONT></P> <P style="margin: 0.0px 0.0px 0.0px 0.0px; font: 12.0px Helvetica; min-height: 14.0px"><BR></P> <P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">I have never seen a piano behave like this in 30 + years of working on them.<SPAN class="Apple-converted-space"> </SPAN>There is always a major shift at each break in the scale. Most times one can even see a slight jump even when the scale is broken/widened at the front termination and not at the bridge.<SPAN class="Apple-converted-space"> </SPAN>I've watched pianos very closely for a long time relative to climatic changes, and what I see is a similar type of movement in each section.<SPAN class="Apple-converted-space"> </SPAN>If the lowest part of the tenor is sharp relative to the rest of the tenor section... then you see the same thing in the tenor/treble break... and the treble/diskant break (up to the last highest octave)<SPAN class="Apple-converted-space"> </SPAN>and in the bass section. <SPAN class="Apple-converted-space"> </SPAN>Same thing in reverse if the low tenor has become low with respect to the rest of its section.<SPAN class="Apple-converted-space"> </SPAN>The pattern is nowhere near as severe in the bass or highest treble (diskant)... but its there.<SPAN class="Apple-converted-space"> </SPAN>I dont think I have ever seen an exception to this <<rule>>.<SPAN class="Apple-converted-space"> </SPAN></FONT></P> <P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">The only part of the piano that doesnt seem to fit into this is the highest octave...especially from F-G7 upwards.<SPAN class="Apple-converted-space"> </SPAN>Seems to do what the low tenor is doing and seems to have a very large reaction.</FONT></P> </BLOCKQUOTE></DIV><BR><DIV>Hi Ric,</DIV><DIV><SPAN class="Apple-tab-span" style="white-space:pre"> </SPAN>Well, I have observed this repeatedly on the Hamilton 243s, Everett studios, and a couple Steinway 1098s I service regularly. There is a gradual increase in the pitch change from about C6 (which is at about "high average" pitch), rising logarithmically to C8. I have found as much as 75 cents on the top few notes, with tenor change being in the 25-35 cent range. Of course, as I wrote earlier, this seems to be "model specific" to a large extent. I don't see it at all in Yamahas, for instance, where often areas in the high or mid high treble can be sharp when the rest of the piano is flat and vice versa.</DIV><DIV><SPAN class="Apple-tab-span" style="white-space:pre"> </SPAN>There's also a quirk to the 243s at the treble break. The pitch change accelerates as you approach it from below, then there is a sharp jog of less change for the first few strings above the break. I attribute it to something to do with scaling and tension, as a guess. Virtually every other piano behaves as you describe above, with mirroring jogs at each break.</DIV><DIV><SPAN class="Apple-tab-span" style="white-space:pre"> </SPAN>In observing this kind of thing over the years (getting to be decades, now), I have found that the data can often be contradictory and confusing (especially if you don't know intimately what has happened to RH in the interim between tunings). I have often intended to start documenting (as in actually writing things down), but the times when the data would be most useful tend to be the times I am utterly swamped and can't spare the time. So I rely on memory, and make short notes in my work log. For instance, I have recently taken to writing "RP 5-25 cents, -50 cents HT" to show that I raised pitch in most of the piano 5-25 cents, but the high treble was as much as 50 cents flat. I have found myself doing this notation a good bit the past few years, and wonder why I didn't notice it years earlier. (I used to distinguish the bass, but stopped bothering. Actually, though, there can be a good bit of variety there as well, from not much change at all to quite significant - again, probably model specific).</DIV><DIV><SPAN class="Apple-tab-span" style="white-space:pre"> </SPAN>Until a large range of data is collected, very specific as to model, humidity history between tunings, and with samples at a good representation of notes, we will be making stabs in the dark. And one would also need to know at least something about bearing and crown to make it really worthwhile. I'm sure my own particular climate affects what I observe, as does yours. I don't get quite the extremes Mark Cramer and others in the frigid north get, but I do get single digits regularly, and up to 80% RH. 10 - 60% annual swing is pretty average. I suspect 40 - 90% would give markedly different results, for instance.<BR><DIV><DIV>Regards,</DIV><DIV>Fred Sturm</DIV><DIV>University of New Mexico</DIV><DIV><A href="mailto:fssturm@unm.edu">fssturm@unm.edu</A></DIV><DIV><BR class="khtml-block-placeholder"></DIV></DIV><BR></DIV><DIV><BR class="khtml-block-placeholder"></DIV></BODY></HTML>