Mr. Finch has a great idea! I have often fantasized about a modern
Fairground/Street/Dance/Band organ, properly configured to correctly
play original books, rolls or drums from old sources, as well as modern
works transcribed electronically.  The suggested specs all are good ideas.

First and foremost, a proper selection of pipes, with a wide selection of
traditional voices, is the prime requisite.  This is not so daunting as
it might seem at first.  In any public MM organ, each voice is typically
used for a narrow range of the scale; in other words, you would not need
61 of each kind of pipe.  Anyway, there are only so many different
fundamental organ voices available, when all the bull surrounding stop
names is scraped away.

An electric action (Magnetic actuators directly operating the pipe-hole
valves), with solid-state logic, is the only way to go to get the
flexibility to handle all the registration and coupling variations
inherent in different original sources.  Surprisingly, speed is no
problem if such valves are properly selected.  

In any case, the software would have to incorporate 'legato adjust',
that is, adjustable time delay for the start or the end of each note.
This would be needed to compensate for the wide range of different
note-overlap or mechanical lag compensations that are inherent in
different original media; mechanically or pneumatically read books,
rolls, or pinned barrels; as well as to overcome the problems inherent
in the different methods by which the original media might be scanned.
Physical compactness, reliability, and long life are also factors which
recommend this approach.

I have always thought that such an instrument should be chromatic, for
three reasons:

1. It would make easy the transfer of original source material, which
used different approaches to the 'diatonic limitation' problem.

2. Transcriptions of modern or classical work, which tend to be more
modulated than some early popular music or marches, would be facilitated.

3. Public acceptance would be enhanced; we in MM tend to put up with the
distortions required to play a mid-century popular tune on a diatonic
instrument, the public does not.

I am sure many others have contemplated this idea, they just haven't had
the nerve to alienate the purists by putting it on the table.  As Mr.
Finch says, the music is the thing.  Preserving it and making it more
accessible to the world, demands that such an instrument be built sooner
or later.

Let's keep this thread going!

Richard Vance