Mechanical songs like "3 Blind Mice" and "Row, Row, Row Your Boat" have been enjoyed for centuries. But mechanical songs can be more than just novelties for children. The short acappella choral songs in this booklet are called "machines" because most of them are built using different repeating patterns (ostinati) in the different voices. Machines can have a transfixing beauty to them. Like a kaleidoscope, the repeating voices juxtaposed in new ways can be fascinating. And when gentle ideas are added to the hypnotic music, a feeling of deep peace can result. Secretary Michael has long pioneered in this art form. These songs were written for adult ensembles but are appropriate for thinkers of all ages.