Wurlitzer Concert Organ Rolls were made "For the Wurlitzer Hope
Jones Unit Orchestra With Roll Attachment" and were the smallest of
several types of Wurlitzer pipe organ player rolls manufactured over
the years. [1]

I assumed the format would resemble the Wurlitzer Automatic Player
Piano (APP) roll format, but two significant differences are apparent:
(1) the paper width and holes per inch are same as standard 88-note
piano rolls, and (2) there are no chain patterns. The rolls were
perforated by the same variable-advance machine that automatically
applied compensation to APP rolls so that dance music tempos wouldn't
accelerate.

The roll I am examining is WCOR number 4093 which contains four
light classic pieces such as selections from "Hansel and Gretel" and
"Falstaff". [2] At the beginning of the roll the initial advance
distance is 0.030 inch, or 400 rows per foot. At the end of the roll
the advance has increased to about 0.045 inch or 267 rows per foot.
The music plays for 20 to 25 minutes.

The music suffers the same repetition problems of APP rolls, i.e.,
trills in the first tune or two are muddy because the paper speed isn't
fast enough to enable fast, clean trills. My goal is to recover the
music as the arranger intended -- as it existed in the sprocket-drive
master rolls.

Robbie Rhodes
Etiwanda, California
rrhodes@linkline.com.geentroep [delete ".geentroep" to reply]

References:
[1] https://www.mechanicalmusicpress.com/registry/wurlitzer/mr_conorg.htm 
[2] https://www.mechanicalmusicpress.com/registry/pdf_data/rpt_roll/Concert_Organ_Rollography_Report.pdf