On several occasions I have observed rolls of the same recording
marked with different paper speeds but with the same playing time.
My thanks to Julian Dyer for giving a reason for this [200419 MMD].

I have also noted Welte-Mignon rolls with large perforations, usually
dated prior to 1909, and the same roll with smaller perforations,
typically from the 1920s.  Julian suggests the two differently cut
rolls would need to run at a different paper speed, but there is no
way this can happen on a typical Welte-Mignon.  I have found that both
cuts, when played at the same paper speed, give the same playing time,
so maybe the rolls were cut in a way that compensated for the
different punch sizes.

In regard to variations in marked paper speed, the worst case I have
seen is Duo-Art roll 5597, "Berceuse" by Chopin. played by Zadora.
I found three original rolls of this recording, one marked Tempo 65,
the second marked Tempo 80, the third marked Tempo 95.  All rolls had
a different playing time commensurate with the marked Tempo.  I chose
the 65 Tempo as most likely to be correct, but who knows.  The problem
with roll paper speed is no matter the Tempo, the pitch does not
change.

Peter Phillips
Sydney
tel.: (02) 9773 4734
https://petersmidi.com/