Unison coupling

[Richard Moody]

> 
> It also is possible that the apparent frequency shift caused by
unison 
> coupling is as small or smaller than the normal frequency shift
caused by 
> loud and soft playing, perhaps making the effect negligible in
practice.
> 
> Kent Swafford

A visit to the JASA site (Journal of the Acoustic Society of
America) has two sample journals to give an idea of what their up
comming CD of back issues will look like. It takes a special viewer
to see them, but it is a quick download. They look like scanned in
bitmap form but much smaller file size.  That means you can't cut
and paste or search as if they were ocr'ed.  
	An article in the 1941
volume was about measuring harmonics and trying to determine if
they were pure.  First they experimented with organ pipes the with
piano strings. 
There were a couple of mentions of coupling, but no references in
footnotes. They had to see if coupling was happening in one
experiment.

The URL is  http://asa.aip.org/djvu/1941/13-2/index.html
The article is http://asa.aip.org/djvu/1941/13-2/07/13b00145.djvu
The title is  Harmonic Relations in the Partials of Organ Pipes and
of Vibrating Strings (page 145) 
 It is readible ---ric