Greetings from New Zealand!  As we have now finished the rebuild of
our 92-key Decap organ, I have been seeking the views of some respected
figures in the world of mechanical music on a philosophical point
regarding tuning.

You may know that the "tremulant" action in this type of organ is not
really a tremulant as the term is understood in the conventional organ.
Instead of varying the applied wind pressure, each pipe in the Jazz
Flute and Vibratone ranks has a small pallet.  These open and close
rapidly, sealing and then opening a hole in the back of the pipe and
creating a warbling or yodeling effect.

The question concerns tuning these ranks.  Is the accepted practice
to tune with the hole in the pipe open, closed, or with the tremulant
operating, i.e., warbling?

We would appreciate your comments.

Michael Woolf
New Zealand

 [ All that I recall hearing are tuned normally with the rear hole
 [ closed.  The rank sounds like any other flute rank until the
 [ "jazz mode" is switched on.  -- Robbie