There is a set of plans available from a web site for building a simple
but very nice organ.  It is made mostly from PVC and uses a harmonica for
the reeds.  It's a very clever design and only costs about US$30 or so.
Sorry I can't give the exact URL; I'm reading this away from home.

Ron Ginger

 [ The step-by-step guide book, "How to Build a Simple Mechanical Organ",
 [ by John C. Kleinbauer, is offered for sale at Joyce Brite's Player
 [ Piano and Mechanical Music Exchange web site,
 [ http://mmd.foxtail.com/Exchange/barrel.htm  -- Robbie