Mike Roseboom wrote: "Does anyone know approximately how many roll-
operated theater pipe organs are in existence today?"

I have a 1929 Kilgen organ (disassembled) with a Rossler-Hunholz player
unit that has four tracker bars.  That's one.  It was originally
installed in a theater on a private estate in Woodside, Calif.  The
player was in the projection booth.

Marc Kaufman