I'm curious about how the old "Metro-Style" rolls were made.  These
are the ones that have a line (independent of the line that marks
the dynamics) running throughout the roll.  The pianolist tries to
track a stylus (attached to the tempo lever) as closely as possible
to the moving line.  Thus, when the line moves to the right, the
tempo increases, and when it moves to the left the tempo slows down.
(A stubbornly independent pianolist might even use the markings as
a basic guide and deliberately vary from them now and then "for art's
sake.")

Obviously, some of the same mechanical principles of roll making are
also at work in the Metro-Style rolls.  If one did nothing to vary the
tempo, the relative spacing of the holes on the paper and the length of
the perforations would themselves create some differences in the tempi
and the note values just as they do on standard rolls.  (But I suspect
it's a matter of degree.  Standard rolls probably do more of this than
the metro-style rolls.

So my curiosity has to do with how the roll makers might have decided
whether to put elements of the interpretation into the roll itself vs.
how much of the finesse they thought was appropriate for the pianolist
to add.

And how did they go about deciding just how to mark the rolls?  One
roll in my collection ("Stars and Stripes Forever") claims to display
the composer's own tempo markings.  That would suggest that Col. Sousa
sat down at a piano and experimented with the controls until he liked
the way the original, "plain vanilla," roll sounded.  Interesting
thought.

And I also wonder how much better (or worse) I could make my standard
rolls sound if I were to dared to experiment with the controls as
relentlessly as one does when playing a metro-style roll.  (I usually
do add my own creative touches, of course, but it's not always easy
to remember from playing to playing what has worked particularly well.
Markings help.)

Chances are nobody is left who was involved in making the original
Metro-Style rolls.  But I'm sure readers of the MMDigest have thoughts
on this matter.

Paul Murphy