This message is intended mainly for Bill Finch, but it would be
interesting to hear thoughts from others.

Bill, I agree the most fun and interesting thing about band organs is the
music, and also the way that the music and sounds are produced.  For this
reason, I abandoned the possibility of using one of the three standard
Wurlitzer scales.

To me, chromatic ranks of pipes and the ability of turning them on and
off in combinations with each other is a must, not an option.  The same
ranks of pipes playing together all the time quickly becomes a din.  If
you have ever heard a Wurlitzer organ play Stars and Stripes or Thunder
and Blazes, you realize how the music must be butchered in order to fit
the "music" scale of the [non-chromatic] organ.  If the organ playing is
a small one, playing a 150 or 125 roll, with little or no register
changes, the music becomes lifeless and boring.

Constructing an organ that more closely follows some European scale would
probably be a more interesting and musical thing to do.  I am assuming
that the music is still the most interesting part for you about band
organs.

As far as using a direct electric action, this probably would be a good
choice, especially if you are designing something for commercial use.
Depending on how you are going to address this sort of a musical system,
you may need lots of blocking diodes, or large gang switches, or many
solid state switches capable of handling the current of many magnets.
Companies like Devtronix sell solid-state products that probably do this
exact thing.

With the flexibility of MIDI address, it would, as you have said, be
possible to address each pipe individually.  This might also make the
MIDI files very large.  It could also create a MIDI log jam, but maybe
not, as I have no experience operating a band organ in this manner.  In
order to take full advantage of this sort of system, you would have to
have custom files created for this organ or be able to arrange them
yourself.  Of course with more special switching hardware you could be
able to play the more conventional type MIDI band organ files that you
mentioned that you have from scanned rolls and books.

If you are planning on building an organ that is to be for commercial
use, these sorts of thoughts are probably the way to go.  If you are
building something as a hobby person, the organ with no moving parts is
pretty boring if the mechanical aspect of a project like this is of
interest.

A good way to see and hear home-built organs, is to go to some of the
band organ rallies.  The biggest rallies this year are July 24 in Sandusky
Ohio, and August 1 in Marion Ohio.  At the Marion rally there will be at
least four home-built organs.  At the Sandusky rally there will be at
least two.  Most of these organs do not play Wurlitzer music, but a few
do, and you can decide for yourself what you like best.

David Wasson