From what I have seen, B.A.B. organs used two single-tap beaters.
The B.A.B. system used a separate perforation for each beater so
it could individually tap out a distinct rhythm, yet still be able
to produce a rapid drum roll.

The Wurlitzer system used two reiterating beaters, controlled by
a single perforation.  The drum roll on this system is very quick
and sounds like a constant sound, so to speak.  My question is,
what are the advantages and disadvantages of these systems?

Will Eley

 [ The B.A.B. system with two independent beaters and two control
 [ channels is the tradition in European book music organs.  The
 [ Wurlitzer system spares one control channel for other uses,
 [ which was important to Wurlitzer I suppose.  Plus, the single
 [ snare drum channel of the master "stencil" for the Wurlitzer
 [ music roll perforator is much easier and faster to create.
 [ -- Robbie