Hello everyone!  My post concerns the playing of Themodist rolls on
pianos with Duo-Art player actions.  I had read Reblitz on this and
(on page 189) he says:

  "Duo-Art reproducing pianos will play Themodist roll accents auto-
   matically, (with the manual levers used for adjusting theme and
   accompaniment volume levels), with the "Duo-Art on/off" lever set
   at the middle (arrow) position (pre 1925 pianos) or in the "off"
   position (post 1925 pianos)."

My instrument, a pedal only half Duo-Art, appears to be slightly
different.  In the "on" position appropriate accompaniment vacuum is
set by the coding on the roll.  Theme vacuum is governed simply by how
hard the pianolist is pumping.  In the "off" position the accompaniment
vacuum is set by default at level 4 so that 88 note rolls are played at
a constant low volume regardless of how hard one is pumping.  To
increase the volume one simply turns the "temponamic" knob clockwise.

In the middle (arrow) position atmosphere is admitted to both cutout
pouches thus disabling notes 1-4 and 85-88 as well as the holes
controlling the accompaniment dynamics.  My interpretation of this
position is that it allows one to play a Duo-Art roll with complete
control of the accompaniment vacuum by means of the "temponamic" knob
and the theme vacuum through the pedals.  Themodist rolls could also be
played in this position but notes 1-4 and 85-88 will not play -- they
should be played in the "off" position which allows all 88 notes to
play.  Theme snakebites are read regardless of the Duo-Art switch
position.

Much of the tubing on this instrument had disintegrated when I
obtained it so that several connections were made only after much
thought.  However I feel that the way it works now is logical (I can
think of no other way to do it).  That it does not agree with Reblitz's
description is perhaps simply a consequence of variations that Aeolian
made from time to time.

Does anyone out there have a similar experience with trying to guess
how the Duo-Art switch is supposed to work?  Did I get it right?

Happy Christmas and a Prosperous New Year to all.

Joyeux Noel et Bonne Annee a tous.

Regards
John Johns