James Engel: An Introduction to Organ Registration$10.00
The author builds a foundation for understanding the classification of organ stops both by pitch (16', 8', 4', etc.) and by timbre (principal, flute, string, reed, etc.). He also deals with mechanical devices such as swell shutters, tremulants, crescendo pedal, etc. An appendix shows the shape of each type of organ pipe. The concepts presented are applied to specific musical examples.