<HTML style="FONT-SIZE: x-small; FONT-FAMILY: MS Sans Serif"><HEAD> <META charset=US-ASCII http-equiv=Content-Type content="text/html; charset=US-ASCII"> <META content="MSHTML 6.00.2800.1400" name=GENERATOR></HEAD> <BODY style="FONT-SIZE: 10pt; FONT-FAMILY: Arial; BACKGROUND-COLOR: #ffffff"> <DIV><FONT face="MS Sans Serif">I haven't found that changes in humidity tend to cause instability in one string of a unison.  When I see pianos moving around from changes in humidity or temperature, it's usually the intervals that go while the unisons tend to stay put.  I would examine hammer technique and how hard you are hitting the string.  It doesn't require a massive blow to create stability, in fact, it may be counterproductive.  </FONT></DIV> <DIV> </DIV> <DIV> <DIV>David Love</DIV> <DIV><A href="mailto:davidlovepianos@earthlink.net">davidlovepianos@earthlink.net</A></DIV> <DIV> </DIV></DIV> <DIV> </DIV> <BLOCKQUOTE style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid"> <DIV style="FONT: 10pt Arial">----- Original Message ----- </DIV> <DIV style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B> <A title=Wimblees@aol.com href="mailto:Wimblees@aol.com"></A></DIV> <DIV style="FONT: 10pt arial"><B>To: </B><A title=caut@ptg.org href="mailto:caut@ptg.org">caut@ptg.org</A></DIV> <DIV style="FONT: 10pt arial"><B>Sent:</B> 4/10/2004 12:35:45 PM </DIV> <DIV style="FONT: 10pt arial"><B>Subject:</B> Re: why does a string go out of tune?</DIV> <DIV><BR></DIV><FONT size=2> <DIV> <DIV>In a message dated 4/10/2004 2:00:24 PM Central Standard Time, pianotuna@accesscomm.ca writes:</DIV> <BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: blue 2px solid"><FONT face=Arial>Hi Wim,<BR><BR>Possibly you are pounding too hard. Very small changes in humidity cause<BR>pitch instability in unisons. I've documented that on the ptg list. I wish<BR>I had better tools to analyse what is going on. Temperature (stage lights)<BR>as I'm sure you know can make huge differences very very rapidly.</FONT></BLOCKQUOTE></DIV> <DIV>I know stage lights can make a difference, but those differences are by way of the soundboard. If the humidity causes pitch instability, why just one one string? Why not in all of them? Why do some strings go up, and other go down?</DIV> <DIV> </DIV> <DIV>Wim </DIV></FONT></BLOCKQUOTE></BODY></HTML>