A bunch of articles relevant to this forum, believe it or not. I started by sticking "pipe voicing" into Google
and this
http://asadl.org/ (http://asadl.org/)
pops up... Lots of fascinating stuff there 8) 8) 8)
Would be even more fun to have the full text of the papers online but this would likely require joining the organization in question... But even the abstracts are fun to contemplate...
Eric
KB7DQH