This definition is given in my 7 kg Merriam's dictionary of 1927:

  orchestrion -- A large music box like an elaborate barrel organ,
  provided with different stops, imitating a variety of orchestral
  instruments.

The critical phrase of the traditional definitions is "imitating
a variety of orchestral instruments."

A mechanical musical instrument that simply plays a bunch of percussion
devices isn't an imitation: drums _are_ drums!  The instrument should be
called a drum machine.  (Some could accurately be called "noise makers".)
A group of live percussionists is usually called a percussion ensemble,
not an orchestra.  (Yes, I know; marimba ensembles often call themselves
a "marimba orchestra".)

The violin playing machines by Hupfeld and Mills may occasionally play
triad chords, but they don't play independent musical voices in imitation
of an orchestra or a string quartet, so they aren't orchestrions.
Besides, violins _are_ violins, not imitations.

That leaves the pipe organ, and people accept that this grand instrument
indeed imitates a variety of orchestral instruments.

So I say that some organ pipes must be played if the mechanical music
machine is to be called an orchestrion.  Many, but not all, instruments
qualify as an orchestrion in my view if the instrument plays some organ
pipes _and_ tries to imitate the sound of an orchestra.

Does that mean a 20-note street organ or organette can be called an
orchestrion?  I think not, because the small organs don't attempt to
imitate orchestral instruments.  They are content to be themselves,
with their own unique personality.  The jolly dance hall organs of
Belgium and Holland imitate a dance orchestra, but I think the owners
prefer the name "dance organ" to "orchestrion".

An A-roll instrument with only a piano and one short rank of flute or
violin pipes is rather dubious, since there is limited variety of sound.
It would severely strain the imagination to be told that this simple
instrument imitates a variety of orchestral instruments.

All this makes me suspect that "orchestrion" is just a marketeer's
(or owner's) attempt to convince his audience that his instrument
is different and better than the competitor's.  The same sort of hype
occurs selling soap ("a dishwashing agent especially formulated to be
environmentally friendly").

Focus on the sound and don't worry too much over the name.  Trust your
senses, not the words of the marketeer, and call it as you hear it,
like "an anemic organ" or "a tipsy sing-along piano".  When you hear
a well-restored Philipps Paganini or Wurlitzer PianOrchestra or Weber
Maesto, you might even think, "Wow, it sounds like an orchestra!"

Shakespeare said: "A rose by any other name would smell as sweet."

Rhodes says: "A nose by any other name still smells."  ;-)

Robbie Rhodes
Etiwanda, Calif.