In explaining transposed band organ tuning to a friend this morning,
the original reason for pipes being stamped with notes that differ from
their actual speaking pitch finally dawned on me. The following refers
to music rolls, but the same logic may be applied to cardboard books.
Certain smaller organs play in a higher key than larger organs using
the same music rolls do. For example, the Wurlitzer 157 and 165 both
play the same rolls, but the 157 has smaller pipes and plays in a
It was easier to mark all test rolls in the same key -- and to stamp
the pipes with the notes marked on the test rolls -- than to have
different test rolls for each size of organ. This way, a factory
technician or amusement operator's organ tuner only needed one test
roll for each organ scale. In 1905, before anybody was worried about
where to set the dial on an electronic tuning aid, they wouldn't have
to worry about transposing the notes written on the test roll either
when tuning a smaller or larger organ.
Undoubtedly, this scheme has been corrupted over the years, with many
examples of organs whose test rolls or books don't match the notes
stamped on the pipes. But I'll bet if we went back to the early years
of production of any specific line of organs, we'd find that this was
what the builders had in mind.
I'll be interested to hear readers' comments on this.