Hi Peter,  Re demonstration rolls, there were several levels of them.
Some were sold to dealers (Rythmodik Demonstration Roll, Connorized
Demonstration Roll, Electra Demonstration Roll) as well as to custom-
ers, often for practice purposes in the home.  These had serial numbers
and were usually a pastiche of several commercial rolls of the day.

Others, such as the Welte, Duo-Art and Ampico demonstration rolls,
would not play music per se, but would demonstrate arpeggios and
crescendi -- usually featuring printed annotations for the customer
to read as the piano went through its dynamic paces.  These rolls also
had serial numbers and standard box labels.

Some, such as the "I Am The Ampico" rolls were long-playing arrange-
ments -- again a medley of existing releases -- were designed for store
window displays and the like.  Usually these were hand-lettered, with
sentences such as "You can hear me play Liszt on the Sixth Floor" and
other custom lines added for the situation at hand.  The "I Am The
Ampico" rolls had large lettering, usually in the middle of the music
sheet, so that passers-by would stop and read the text.

Finally, there were rolls that "toured" with the pianos.  The erratic
Bauer and Grainger rolls I have were from the 1919 and 1921 San Fran-
cisco concerts, co-sponsored by Sherman & Clay (stores) and Aeolian
Hall.  These were concerti and required an orchestra or a second piano.
They were used for concert performances at the Palace of Legion of
Honor (art museum) and the Central Theatre on Market Street.

And then there are some mystery rolls, such as the Rhapsody in Blue
(Primo) with no serial number, designed for in-house performances and
quickly made (as an Armbruster letter [here] from the '70s indicates)
and featuring pencil scratches in order for the 2nd pianist to see
when to stop/start playing.

These hastily-made rolls didn't have special perforations for a
prepared Pianola, which often involved retubing the rewind/shutoff
holes on the tracker bar, or special perforations for the remote
controls in the podium, or off-stage.  This Rhapsody in Blue Duo-Art
roll is fantastic, even as a solo piano performance.  The Armbruster-
sounding commercial rolls (2) are just so much musical wallpaper, by
comparison.  Regarding the mystery roll, it runs at Tempo 100.  The
released Gershwin work begins at Tempo 65: "snore...!"

If a dealer needed something special or a promotional concert was in
the making, things were whipped up in a hurry.  Knabe, for example,
invited prime clients and piano dealers to their heralded "Affair at
the Biltmore" concert with Godowsky.  The piano stalled, but the
advertisements rattled on for years about the reproduction (ruined due
to the interruption of mechanics having to adjust the player action).

The 1919 Cleveland Orchestra, with the Duo-Art racing along faster
than normal, was also for an invited audience, and subsidized with
funds from The Aeolian Company.  Once over, these events could be
used for newspaper publicity and future advertising, even if the
performance itself was a musical disaster.  (That's the beauty of
having a _selected_ audience, just as politicians often use for their
press conferences!)

I also have some commercial Duo-Art rolls with pen knife expression
and soft/sustaining pedal changes, which make them more exciting than
the home versions.  These often feature a soft pedal at the start of
the crescendo (cut with a pen knife) and include extra dynamics at the
end (via more knife cutting).  Additional (trapezoid!) knife cuttings
add considerably more Themodist (solo) accents as well!

The hand-edited demonstration version of Cortot playing Etude in the
Form of a Waltz is a good example in my library; one is bland and
essentially background music, and the edited copy sparkles, as it
should for Duo-Art stage presentations!  Most of these custom-edited
rolls have a sloppy appearance, being done with hand knives, but the
performance is always several stages above the clean-looking and
generally boring commercial equivalent.

Hope this sheds a little light on the field.

There are no rules in music, an aesthetic pursuit, so it follows
that there weren't any in the elusive sphere of Demonstration Rolls!

Regards,
Douglas Henderson

http://www.wiscasset.net/artcraft/