I hoping someone can tell me, via the MMD or email, the vertical
resolution of a reproducing piano roll.  That is, during production
of such a roll, I want to know how far it moves between punches.
I understand this resolution is higher than for a player roll.  And
is this resolution the same for all systems (Duo-Art, Ampico etc.)?

Peter Phillips
(Australia)

 [ Wayne Stahnke determined these measured and/or intended
 [ rows per foot for common reproducing piano rolls:
 [
 [   early Duo-Art: 256 rows per foot nominal
 [   late Duo-Art: 379.5 rows per foot
 [   Poughkeepsie Welte-Mignon: 500 rows per foot
 [   Welte Licensee: 403 or 540 rows per foot
 [   early Ampico: 240 rows per foot (until about 1921)
 [   later Ampico A rolls: 356 rows per foot (confirmed by Ampico)
 [   pop music rolls: 240 to 360 rows per foot is typical
 [
 [ To my ears there is no correlation between the rows per foot and
 [ the musical performance quality of an original roll or disc or
 [ music book.  Recut media are generally inferior quality unless
 [ copied with great care.  -- Robbie