Frank Himpsl sent me some photocopies of an original Columbia/Capitol
"A" roll, and from it I see the following:
12 rows / quarter
20 rows / inch
This works out to a basic tempo of 120 beats/min and 60 feet in 1 min.
From that I gather:
medium tempo -- 12 rows/quarter
up tempo -- 8 rows/quarter (makes triplets hard)
cut time -- 6 rows/quarter
"Up tempo" may be 9 rows/quarter, but that would make evenly spaced
8th-notes impossible. I need confirmation of this from somebody.
[ I'm told that there was a fine article about this topic in the AMICA
[ Bulletin, within the past ten years, and it was written by someone
[ like Dave Junchen or Art Reblitz who is expert at arranging music
[ for mechanical instruments. -- Robbie