Hi All, while perusing the 'net I came across The Organ History
Welcome Page at http://panther.bsc.edu/~jhcook/OrgHist/welcome.htm
that has some interesting animations of the workings of pipe organs
and, in some places, movie clips showing "things" in operation.
It also has some sounds comparing different pipes and so forth.

Another one is The Physics Of the Organ at
http://panther.bsc.edu/~hahancoc/organwebsite/ that has some good
descriptions of the way pipes sound, along with some calculations, etc.

Later,
Mickey Sadler,
Dublin, Ohio