by Sam Cronk

The organ has been called one of the most complex of all mechanical instruments developed before the Industrial Revolution. Despite their size, organs operate on the same principle as do hand-held panpipes - sound is produced by air which moves through pipes of different sizes and lengths. The pipes of an organ receive air from bellows or through valves controlled by one or more keyboards (called manuals) and a keyboard for the feet which is made up of pedals.
There have of course been many changes in both construction and performance techniques. Before the age of J.S. Bach (1685-1750), organists did not usually pull more than one stop for the same pitch. However, by the 1700s, organists began to use Òorgano pleno,Ó or the full organ. This movement toward a bigger sound quality is mirrored by a movement toward bigger-sized instruments.
In the 19th and 20th centuries, an increasing interest in authentic baroque music and instrumental sounds encouraged many 17th century organs in Europe to be restored, and many copies of these instruments to be recreated in the United States. The Fisk organ, part of the University of Michigan Stearn's Collection, is a reproduction of a model constructed by Gottfried Silbermann, an 18th century German mastercraftsman.