David Wasson asked, "Why didn't Ampico, with precision automatic
perforators, compensate the tempo?"

Well, they did and they didn't!  All rolls recorded before 1926 (when
Dr. Hickman modified the process) were not compensated; after that date
all classical music rolls and some of pop rolls _were_ compensated,
such as the Dinner Music series.

The hand-played recordings of Ampico's Classical Music Department were
registered with a recording piano which marked the key events on blank
paper.  After 1926 the paper was pulled by a take-up spool, but earlier
classic rolls and all pop rolls were produced with constant paper speed,
and so would play correctly only if pulled with a capstan-drive spoolbox
or equivalent.  It's true that the speed/tempo increases slowly as the
song is played, but Ampico seemingly ignored the matter!  (The Ampico B
has a take-up spool of much larger diameter, and so the acceleration is
less noticeable.)

Wurlitzer, however, was perforating long-playing music rolls for their big
orchestrions and organs, and so they had to provide the compensation for
the increasing paper speed.

Even though the tempo increase of a 3-minute pop music roll is only about
5%, it nonetheless annoys me!  I have an urge to add a compensator to
the motor in my Ampico B, which would keep the paper speed constant by
reducing the motor speed as the diameter increases.  I just need a little
time, though ...!

Robbie Rhodes