<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META content="text/html; charset=iso-8859-1" = http-equiv=Content-Type> <META content="MSHTML 5.00.2920.0" name=GENERATOR> <STYLE></STYLE> </HEAD> <BODY bgColor=#ffffff> <DIV><FONT face=Arial size=2>Hi Alan et al.,</FONT></DIV> <DIV> </DIV> <DIV><FONT face=Arial size=2> <DIV><FONT face=Arial size=4>>> Ah, you were so close to = naming it. It's called longitudinal inharmonicity, When strings vibrate, they don't just = go up and down, as sketches of string motion are drawn. They move in all = directions, very complex. Simply put, the strings in question are some combination = of damaged, poorly made, dirty, corroded, stretched out, or just old. The = motion in one or more directions is hampered in some way so the string harmonics = are "fighting" each other, i.e., not matching up, going out of phase.</FONT></DIV></FONT></DIV> <DIV> </DIV> <DIV><FONT face=Arial size=2>Very cool.  Now I know the name. <smile>  Just to expand on this concept, if the impulse (i.e. = hammer blow) delivered to the string has both vertical and horizontal = components, and if the vertical and horizontal components are not simple scalar = translations of each other (i.e. that the horizontal force is a fixed multiple of the = vertical force, such that they could be resolved as a simple, unidirectional = impulse at an angular direction -- highly doubtful), then the initial horizontal = and vertical spectra would have different relative representations in the = different harmonics (partials).  As a result, the resultant angle of = vibration would differ between harmonics.  (Think about it.)  Now, considering = the inharmonicity of the string, the phasing of the different harmonics = would drift.  As they drift, angle of vibration at any given position of = the string would also drift, i.e. being the sum of the vibrational = components from each harmonic, which arguably are set at different angles in an = imperfect system.  Add to the cocktail that nonlinearities in string behavior = would result in the gradual transfer of energy from lower frequencies to their = harmonics in the *same* vibrational direction as the lower frequencies, with those frequencies summating with the (slightly = different frequency) harmonics at different vibrational angles, thus causing = a shift in the angle of the resultant vibrational component.  YOW!!  WOW!!  This could make a person's brain bleed!</FONT></DIV> <DIV><FONT face=Arial size=2></FONT> </DIV> <DIV><FONT face=Arial size=2>ANYWAY....  I think the answer = with regard to the non-yowing Bosendorfer vs. the other yowing pianos is probably = the absence of horizontal components in the initial impulse to the = string.  That is, (1) the hammer is better balanced on the shank, such that the = shank doesn't twist when set into motion; (2) the hammer's center of mass = moves perfectly in-line towards the strike point = (not with respect to the arc of it's swing); (3) the centers are tighter, = resulting in less play; (4) the hammers are more uniform and/or less = grooved, such that the string is not "tapped" slightly to one side; (5) other factors = that you piano techs would know better than I would.  Basically, it's a more = precise motion that delivers, say, a 99.5% vertical and 0.5% horizontal = blow, even after all the twisting and flailing that the hammer undergoes en route = to the string.  Perhaps the extra care in manufacture?  = Perhaps luck of the run?  </FONT><FONT face=Arial size=2>Perhaps it's = also partially related to the use of hornbeam, which I recall flexes less???</FONT></DIV> <DIV> </DIV> <DIV><FONT face=Arial size=2>I remember taking lessons as a = teen on my teacher's concert Bosendorfer.  Cool piano!  I think she loved = that piano like a child.  Still, I confess I didn't enjoy = it as much as a beat-up Steinway B</FONT> <FONT face=Arial size=2>in one = of the practice rooms at my alma mater.  The piano didn't look like much, = but it sang beautifully -- even if it might have yow-yow'ed a bit!</FONT></DIV> <DIV> </DIV> <DIV><FONT face=Arial size=2>Peace,</FONT></DIV> <DIV><FONT face=Arial size=2>Sarah</FONT></DIV> <DIV> </DIV> <DIV> </DIV> <BLOCKQUOTE style="BORDER-LEFT: #000000 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: = 0px; PADDING-LEFT: 5px; PADDING-RIGHT: 0px"> <BLOCKQUOTE style="BORDER-LEFT: #000000 2px solid; MARGIN-LEFT: 5px; = MARGIN-RIGHT: 0px; PADDING-LEFT: 5px; PADDING-RIGHT: 0px"><FONT face=arial,helvetica><FONT face=Arial lang=0 = FAMILY="SANSSERIF"><FONT size=2> = <DIV> </DIV></FONT></BLOCKQUOTE></BLOCKQUOTE></FONT></FONT></BODY></= HTML>