If you find a copy of the old Weber Maesto records made by Hathaway and
Bowers in the early 1970s, you'll occasionally hear the triangle
playing at the rate of fourteen times per second.  The music (not the
roll) is playing at a tempo of 140 half notes per minute, (280 quarter
notes), with the triangle playing quarter note triplets.  280 beats per
minute x 3 triplet notes divided by 60 seconds = 14 per second.

It used to be thought that the Maesto could repeat faster than any
other instrument because of its unique pneumatic system, in which the
primary valves feed either air _pressure_ or suction to the secondary
pouches, (instead of atmospheric pressure/suction used in other
instruments.  The pressure is supplied by the pressure reservoir).
However, the triangle and wood block in the Hupfeld Pan are also called
upon to play quarter note triplets in certain rolls, for the same
14-per-second rate.

The Pan has by far the most complicated pneumatic system ever used
in any fully-pneumatic automatic musical instrument (excluding the
largest Moller Artiste organ players, which are electro-pneumatic),
enabling it to play an 85-note piano, 36-note melody pipe range and
61-note counter-melody pipe range, with percussions, reproducing piano
expression and three independent sets of variable speed swell shutters
from a 124-hole roll.  This involves a virtual maze of tubing, pouches,
valves and mechanisms.

All of that extra pneumatic multiplexing and coupling apparatus doesn't
slow down a well-restored Hupfeld Pan at all, leading me to believe
that any simple pneumatic mechanism can play at least 14 times per
second, given the right hole size and spacing in the roll, bleed size,
relative size of pouch, valve and pneumatic, and roll paper speed.

An article in the Piano Technicians Journal some time in the last year
described testing which proves conclusively that bridle tapes do
enhance repetition, but I don't remember if the article cites the
repetition rate.

Locking the keys "off" in an upright reproducing piano enhances
repetition, especially when playing softly or when playing certain
recuts.  This is why the Philipps Paganini, with its extremely long,
weighted keys, automatically locks the keys whenever a roll is played.

It is the piano action itself that is the limiting factor in repetition
speed, not the player mechanism.

Art Reblitz

 [ I'm happy to have that fact confirmed.  Corollary: tracker bars
 [ with tall holes, and music rolls with 'tall holes', require faster
 [ roll speeds to achieve fast repetition.  It's merely a compromise
 [ of the tracker bar and roll geometry, and not a deficiency of the
 [ rest of the player action design.  -- Robbie