In response to Peter Both's posting [200614 MMD] the following may
be of interest.

The plerodienique was one of a number of music box designs devised
to achieve long playing time.  The system was invented by Albert
Jeanrenaud.  He was father was Arthur Jeanrenaud, originally from
Métiers, about 15 miles from Yverdon.  At the beginning of 1870 he
was established in Sainte-Croix.  Together with his brother Louis
they produced cartel movements.  He patented the plerodienique
design in the USA on 31st October 1882, patent 266,826.

The system was also used by Arthur's successor, G. Mermod-Bornand.
Production ceased at the end of 1894.  His son, Paul Jeanrenaud,
followed in his footsteps opening a factory in Ste.-Croix manufacturing
all types of musical boxes but it was the end of an era for Saint Croix
and musical boxes in particular.  He moved into phonograph and automatic
piano production.

Albert assigned the patent to M. J. Paillard of New York, a member of
the extensive Paillard families.  Comparable patents were also assigned
to Paillard in Ste.-Croix.  It was shown first at the Industrial
Exhibition of 1882, London.

There were two main Paillard families.  The exact business and working
relationships are complex but are covered in "The Music Makers of
Switzerland" (available from the Association of Musical Box collectors,
AMBC).  Sufficient to say that the late H.A.V. Bulleid did not include
a Plerodienique tune sheet in his Tune Sheet Book.

The principle of operation is simple but technically complex to
manufacture and to apply the musical arrangement.  The purpose of
the patent was to use a pair of standard cylinders, mounted on a
single arbor, to play a long, complex, musical arrangement without
interruption -- a tour de force for any musical arranger let alone
the manufacturer of the musical movement.

The two cylinders rotate together on the common shaft.  Each has
a snail cam that moves the cylinder in steps in the conventional
tune-change manner but they do not change position in unison.  They
change in sequence, first one and then the other with the two steps
continuously repeated according to the number of steps cut on the
snail cams.  The steps are the same on each, usually between 6 and 8.

The arranger ensures that there is no break in the performance when the
cylinders move.  Each cylinder has a conventional longitudinal tune gap
at the end of a revolution.  It allows longitudinal movement without
cylinder pins fouling comb teeth.  The arranger had to programme a very
long air without interruption.  The difficulty was to ensure continuity
of music as each cylinder was subject to axial movement at the tune
gap.

The cylinders sit on the common arbor with a gap between them.  The
gap is covered by a loose sleeve.  The gap decreases at each step
change of the snail cams.  At the end of play, both cylinders drop
off the highest step of their snail cam in the conventional manner
and return to their original positions with the original minimum gap
between them.

The movements seem to be the Sublime Harmonie type, one comb for each
cylinder.  They are also thought to be Rechange (Interchangeable)
movements.  The sublime harmony effect was achieved in the usual way
by two combs, tuned to the same scale but with slight differences in
pitch.

The original Rechange type of interchangeable movement meant that all
the cylinders had to be purchased at the time of placing an order.
Later interchangeable movements had sufficient mechanical clearance
between cylinder and comb to allow subsequence purchase of cylinders.
It is not known if this was the case for Plerodieniques.

Plerodieniques were always expensive and are rare.  There are two known
makers, perhaps only one who supplied the other.  They are either one
of the two main Paillard families and/or Mermod.  Of the two families,
Paillard-Vaucher fils (PVF) is the most likely candidate, the
letters PVF being on a tune sheet with the title: Sublime Harmonie
Plerodienique.  However, an advert in the C. Paillard catalogue of
1895, the other family group, describes their interchangeable
Plerodienique-Sublime Harmonie with 21 x 3-inch cylinder.

The term Plerodienique almost defies translation and is clearly an
invention, with connotations of Greek and Latin.  It is as original
and almost as meaningless as "Supercalifragilisticexpialidosious"!
But it does what any good marketing agent wants; it is memorable and
conveys a sense beyond mere quality (think of the German advertising
slogan: "Vorsprung durch Technik"[*], unintelligible to Audis'
non-German speaking market.)

The Association of Musical Box Collectors is producing another book
for issue in 2021.  Plerodienique tune sheet examples are welcome.

Paul Bellamy
Rochester, UK

 [ * https://www.theguardian.com/media/2010/jan/22/audi-vorsprung-durch-technik-trademark 
 [ -- Robbie