While I am a bit of a purist when it comes to this subject, I would
say that there is always a gray area that can be worked around.

Welte orchestrions were sent back to the factory to replace the barrel
mechanisms with roll playing mechanisms.  So, if they made a major
modification to _modernize_ a historical machine, can it be wrong?

You can make the obvious argument that they made the original machine
so they could modify it as well.  I'm not recommending that someone
with an original Welte orchestrion modify it now to play "O" rolls or
something like that, but historically it can now be excused in some way
-- the customer wanted it to be state-of-the-art and with the new
technology, they met the demands.

 [ When a manufacturer modifies a previously sold product, the action
 [ is generally called "upgrade" or "enhancement", even if it's just
 [ repairing a problem that existed when it was first sold.  This is
 [ true nowadays for many complex products, from computers to airplanes.
 [ Fortunately, I don't think the mechanical music industry was ever
 [ forced to recall products to fix a potential hazard.  -- Robbie

My personal take on the issue is based on a few principles:

1. Do no damage.  Everything should be reversible to bring the
instrument back to the original state.  A large group of people are
currently scanning rolls to generate MIDI files -- saving the music
for a time when our paper rolls will be dust.  It's easy to convert
a piano to accept MIDI format: simply insert the MIDI-roll player
_in-line_ with the existing roll reading device and you have a MIDI
player.  It still allows you to play rolls the traditional way.

2. Reversible.  If you make a modification, let it be one that is
easily returned to its original state.  For example, don't remove
a player system from a Mason & Hamlin Ampico B to install a solenoid
player system.  If you want to MIDI-fy the M&H, use a system that is
compatible with the setup.  If you want to remove the Ampico B system
from the Mason & Hamlin, contact me first -- I'll trade you for one
that wasn't an Ampico!

3. Improve.  Adding cement to the cylinder of a musical box improves
the sound (this is the general consensus).  You can easily melt the
cement and take it back out.  (I don't know if enough cement comes out
to make it completely reversible so if not, please don't flame me --
it's your choice, not mine and I did not have cement added to my
sectional tooth keywind.)

4. Even if you've met all of the above principles, don't modify a rare
and unique instrument.  Chances are if you modify it -- even with the
best of intentions -- it will probably end its days that way.  So, if
you have a barrel operated Welte orchestrion, live with the fact that
you can't control it through MIDI.

How do we define rare and unique?  That's a judgment call that everyone
will have to make for themselves.  I would say if someone wants to add
an instrument to their orchestrion, let them (as long as it meets the
above).

Best regards,
Eliyahu Shahar