In response to the request for MIDI files posted in MMD 030824, I would
offer the following comments.

The paper that Aeolian used to make the rolls has survival problems due
to acid.  In 1998 I started a project to preserve as many Aeolian organ
rolls as possible.  That project included the acquisition of an Aeolian
player pipe organ and a large collection of rolls in two formats.  The
earlier rolls do not control the organ stops automatically and are
known informally as 116-note rolls.  The later version, which controls
all functions automatically, is known as Duo-Art Music, or informally
as 176-note rolls.

These fully automatic 176-note rolls operated a behind the scenes
toggle switch bank known as a "jack box".  These jack boxes are often
overlooked as part of the player system.  Today, there are a number of
unrestored, existing players that no longer have the required jack box.

Both types of rolls use the same tracker scale to play the notes.
Using two rows of staggered holes, two manuals of 58 notes each can
be controlled by these rolls.  Each row uses the spacing of six holes
per inch.  That results in the paper being punched at twelve holes per
inch.  The small holes and close spacing give rise to many tracking
problems on paper that is prone to self-destruct.

Converting these rolls into MIDI files is not a simple task.  The
early 116-note rolls require tempo changes, which are marked on the
roll.  Additionally, Aeolian incorporated a system of changing the row
assignments.  If the roll is marked "Normal", the top row of holes
controls Manual II (swell) and the bottom row of holes controls Manual
I (great).  There is a lever for this setting.  The other lever
positions are, "Reverse" and "Unison".  "Reverse" will of course
flip-flop the row assignments, and "Unison" ties both manuals together.

As the roll is played the operator is instructed by printed words,
much like a song roll, to set certain stops, operate the expression
pedals, select the tracker row assignments, and change the tempo.  So
as this roll is converted to MIDI, a straight reading into a computer
file just won't work.

Reading the 176-note roll is much simpler, with a few exceptions, and
only tracking issues remain as a big problem.  Some very early 176-note
rolls still use the "Normal"-"Unison"-"Reverse" scheme.  Later versions
of these early rolls are issued without the row switching scheme.

When I started this project, no optical reader existed for the organ
format.  I elected to read the rolls by traditional vacuum means.
I read the rolls at a very slow tempo, using an Ampico B roll drive
motor and a specially modified spool box.  After a successful
recording, the "offset" is adjusted so that the playback tempo is
correct.  To date, my MIDI files are almost exclusively from the
176-note rolls.  The standards that I will use to record the 116-note
rolls are still under development.

There are other collectors who are recording rolls.  I know of no
others that are using my methods. I have invested a considerable amount
of money and time in this project.  It is unclear if that investment
will ever pay off, but to date, I am unwilling to give away what has
cost so much to attain.  My worst fear is that inaccurate MIDI files
of these rolls will be circulated.  Very few people understand how the
Duo-Art coding operates all the functions within the automatic system.
Considerable effort is required to make an accurate emulation of the
"jack box" toggle system and switch bank that is "key" to automatic
playback.

The master artists who recorded some of these rolls left quite a gift.
Recently, a very large auditorium organ was used to preview Marcel
Dupres' Duo-Art version of his Prelude in G Minor, roll 3362, with
amazing results.  While this was an exciting event, the prime purpose
of my work is to preserve the roll content and play the results as
originally intended on a properly restored Aeolian Residence Pipe
Organ, such as my 3/34 Opus 1280.  Restoration continues.

I am still acquiring good condition 176-note, Duo-Art organ rolls in
hopes of copying all 539 rolls issued.  Please contact me for trades
and acquisitions.

Bob Taylor