Piano rolls were made for many different uses, and each ought to be
approached correctly if you want to be authentic.  Original trade
literature tended to draw a distinction between the "mechanical piano"
and the "artistic player piano".  The names say it all.  Much of the
present debate seems to be based on forcing the conventions of one type
of roll onto another, typically imposing the lowest expectations on
everything else -- the bane of the mechanical music hobby.

Plain 65- and 88-note rolls are all meant to be expressed as appropriate
for the music.  Classical music cut directly from the music should be
interpreted by the pianolist exactly as if they were playing the piano
by hand.  The makers always meant this to happen: Aeolian's Metrostyle
Themodist classical rolls, for instance, and the many arranged classical
rolls that other companies made complete with carefully-printed
interpretation guides.

The idea of all of these was that the roll provided the "technique" --
the notes -- and the operator provided dynamics and tempo/rubato.  You
could (so said the early claims) forget the complexity of getting your
fingers to hit the right keys and instead concentrate on the
interpretation.

Pop tunes rely on the performer adding to the basic sheet music, so the
"hand played" roll was devised: a complex product often based on true
performances capturing a pianist's ideas, reconstructed by the roll
editor in augmented strict-tempo form.  Expression was encouraged, such
as QRS rolls from the early 1920s with varying-sized dots down the margin
to indicate dynamics.  Because much of the musical character lies in
the notes, significantly less interpretation is required to get these
to sound pleasing.

Quite a lot of companies took a lot of care to educate owners how
to play artistically: for instance, Gulbransen issued 6-roll sets,
Cable-Nelson an "Instruction Roll" complete with booklet, Aeolian a
"Pianola Practice Roll" whose booklet, "On playing the Pianola", can be
found at the Player Piano Group web site (www.playerpianogroup.org.uk)
under the "player pianos" heading.

Despite all this, it's quite amazing how many people insist that
playing these rolls with no expression is "authentic".  Nothing could
be further from the truth.

As with any recording, care should be taken to capture the best
performance from rolls.  Arranged classical rolls should be interpreted
as carefully as if the music is being hand-played.  Popular rolls
should be sympathetic to the music and the pianist's style, studying
disk records, if available, to capture their feel for dynamics and
accenting.  To some extent this is a counsel of perfection, I know,
but there's enormous fun to be had from trying to get the best from
the instrument.

Out-of-tune, worn hammers, expressionless or shriekingly-inappropriate
expression -- you name it, someone likes it.  Being a musical masochist
at home is fine, but don't be a musical sadist and force these
standards on others!

Julian Dyer