Since my first involvement with mechanical music, I have been curious
about the coding of rolls.  In the case of the Ampico, I discovered
that the popular belief of a seven-step system in the "A" format is
woefully short, as the true scheme has many more steps employed.  The
"Baby Spinet" Ampico is the only system that really operates on the
seven-step scheme.

While I have the Ampico coding mostly sorted out, some of the coding
on Aeolian Pipe Organ Duo-Art rolls is still puzzling.  My attention
is focused on the use of the Echo organ on those rolls.

Most Aeolian organs do not have an Echo division; perhaps 30 percent
of the installations have an Echo.  The 116-note rolls have printed
instructions for manually turning on and off the various stops and
include guidance for using the Echo.

If the Echo is to be used somewhere in the roll, the initial
registration at the beginning of the roll states "Prepare Echo -
String, Flute, Vox".  This means those stops are turned on before the
roll begins but they remain silent until later when the instructions
call for coupling the Echo to one of the keyboards.  Some of the fully
automatic, early Duo-Art rolls are also stamped with instructions
similar to the 116-note rolls.  Again, the same "Prepare Echo" routine
is used.

As the collectors in the UK know, Aeolian was very keen on user
interpretation with an extensive library of "Themodist" rolls for the
Pianola.  For some reason, that attitude was strongly present for the
Duo-Art organ, as Aeolian continued to make 116-note consoles for over
ten years after the [176-note] Duo-Art was introduced.  They even made
the free-standing Aeolienne Player for 176-note Duo-Art rolls which
did not read the roll coding, but rather, the user had to sit at the
Aeolienne to control the organ stops.

Drawing on the printed instructions, general consensus has always been
that if the Echo is to be used, the three stops of "Flute, String, and
Vox" on the Echo are to be on.  So with that in mind, my study of roll
coding began.

Soon I discovered several things.  First, I discovered that the Swell
organ, which is turned off while the Echo is on, continues to have stop
changes during Echo operation.  This now muddies the water in trying
to figure out how the Echo organ is to be used.  Does this mean the
Echo should be changing stops, too?  If so, that means the standard
formula of "String, Flute, Vox" is wrong.

Next, I discovered on roll 3415, "Will O' the Wisp", that when the Echo
turns on, _all_ stops on the Swell are turned off.  This means for the
roll to play, something has to be hard-wired to the Echo on the jackbox
(switching mechanism for automatic stop activation), even if the organ
does not have an Echo!

I know my audience is limited, but if all who own that roll could study
it and offer feed back, I would be most appreciative.

Other oddities (errors) have been found in the coding of the Duo-Art
organ rolls, but that is for another day.

Bob Taylor
Missouri