Music Trade Review -- © mbsi.org, arcade-museum.com -- digitized with support from namm.org
JANUARY 26, 1918
THE MUSIC TRADE
REVIEW
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The Second Instalment of a Record of Experiments Which Have Been Con-
ducted During the Past Year to Determine Means of Improving the Expression
Control of Player-Pianos—Some Suggested Improvements in the Construction
Last month the writer described the nature
and results of certain experiments undertaken
during the year 1917, the purpose being to
find out how far one might go in overcoming
some of the admitted limitations of the player
mechanism, viewed from an expressive stand-
point, whilst retaining the ordinary foot-control
and avoiding any and all innovations of an ex-
pensive and complicated nature.
The general idea of the expression mechanism
as modified and adapted by the writer, was ex-
plained last month. It now remains to speak
of certain other changes which are believed to
be advantageous and progressive.
The Non-Speaking Elements
It is a well-known fact that the non-speaking
parts of the pneumatic action constitute a very
large part of the load which the bellows-work
must carry. So long as the principle of 'foot-
control is adhered to for the actual touch on
the piano action, it is obvious that the problems
of providing for these non-speaking elements
is one of considerable complexity. It will be
admitted, we think, that no one has yet devised
a method superior, in principle, to that of foot-
touch upon suitable power-producing elements,
for creating, in the many variations required for
the purposes of piano tone-productions, the nec-
essary impulses at the piano action. The orig-
inal notion of the foot-driven, foot-controlled
player has never for a moment been superseded
since; and every attempt to provide a substitute
for this power-driven bellows-work has been
made for other reasons entirely.
These other reasons, however, are extremely
important. The Ordinary player action, with
bellows-work driven by foot-power only, labors
under the disadvantage that the same plant must
produce power in varying load for playing and
in fixed loads for each of several other inciden-
tal and necessary working parts of the mecha-
nism. In consequence of this, it has been ob-
served, from the earliest days of the art, that
the expressive elements in the bellows-work
are always being overwhelmed by the non-ex-
pressive. In other words, it is not possible to
provide a bellows-system which shall be the best
possible for rapid and great changes of power
from minimum to maximum, and also best for
power output at fixed pressures. The bellows
cannot at once be a fixed-pressure and a va-
riable-pressure device. Therefore it is primarily
made as a variable-pressure apparatus, and the
fixed pressures are provided by governing ap-
paratus placed between the bellows and the
elements that require the fixed power.
But ultimately this simply means that the bel-
lows must always be providing a minimum of
power which is always fixed; for the interme-
diate governor devices must be supplied con-
stantly, and unless the minimum they require
is given them, the apparatus depending on them
comes to a stop. To put it very simply, you
have to pump always so that you get enough
power to keep running your motor, your sus-
taining pedal apparatus, your automatic tracker
device, etc.; and to the extent that this is nec-
essary, your freedom for expression is ham-
pered.
Removing the Load
That this load tied around the player-pianist's
feet, as it were, is heavy and galling, can easily
be found by the simple process of removing it
altogether. In a word, if the various non-speak-
ing parts, such as the roll-driving motor, tracker
device, sustaining pedal pneumatic, etc., are pro-
vided with power from another source, the free-
dom, lightness and efficiency of the foot-work
are seen to be so remarkable that they attract
the notice of the veriest tyro.
There is no doubt whatever that if the prin-
ciple of separate power plants for the speaking
and non-speaking elements be carried out con-
sistently and efficiently, and if the playing bel-
lows be simplified accordingly, as it may well
be, a new era in expressiveness and ease of
playing dawns for the player-pianist.
Last month the writer described an improved
accenting and accompaniment-regulating ar-
rangement. This month the liberation of the
bellows is described.
Simple Changes
As the writer's intention was to make a defi-
nite separation between the power plant for the
non-speaking elements and the playing-bellows
operated by the feet, he set about doing this
by making a few simple changes. Many player-
piano actions are so built that the motor-gov-
ernor and tempo-box are integral with the bel-
lows-system. In most of such actions, however,
it is obvious that the hammer-rail lifts, if any,
the automatic tracker device, and the sustaining
pedal pneumatic, will be separate elements. In
the case of these last, therefore, it is only neces-
sary to disconnect the suction-tube from each
of the bellows, and then block up air-tight the
nipple where the tube runs into the main bel-
lows. That is the first step, and the blocking
may' be done tightly with corks, which have the
advantage that they may be at once withdrawn
when the experiment is to be terminated.
Where a tempo box and governor for the
motor are separate from the main bellows, there
is no difficulty in treating them the same way;
but where they are built in, a somewhat dif-
ferent method is necessary. In the latter case,
then, one simply traces the channels till one
finds the point where the passage is drilled be-
tween governor and the interior of the bellows.
The governor must then be taken down and the
passage in question sealed by gluing over it a
piece of bellows cloth. Then make a wooden
block, say two inches thick, about one inch
longer and broader than the side of the gov-
ernor which fits on to the bellows. Cut in it a
hole the same size and in the same relative posi-
tion as the one you have just sealed. Then,
at right angles to this, in the body of the block,
drill another hole of same size, till the two meet
in the interior of the block. Fasten the gov-
ernor on to this block, and the block to the bel-
lows, in the same position as the governor orig-
inally occupied, using same screw holes.
Now, if you put a nipple at the point where
the right-angle channel you have made emerges
from the block, you are ready to connect up
with your source of power.
The rewind valve of the motor is in the tempo
box, of course, running directly into the bellows.
If you wish to have the rewind run on the
power-drive, as, of course, is much better, you
stop off the rewind hole, make another block,
bore it in the same way as before, place tempo
on block, and block on bellows, looking out for
your tempo and rewind connections so that the
change in height of box above bellows will not
upset things. You then insert nipple as before
described.
The Power-Plant
The power-plant can now be hooked on. It is
only necessary to provide a large block, bored to
receive each of the suction-tubes from motor
governor, tempo box, sustaining pneumatic, soft
pneumatics, automatic tracker, etc., which bor-
ings will terminate in one large central bore,
this in turn being closed with a large metal nip-
ple, same size as action suction tube nipple of
the ordinary player action, with a hose leading
to the power-bellows.
[Before speaking of the latter it may be well
to say that the methods here described for iso-
lating the non-speaking elements from the bel-
lows may seem crude. They are crude, but it
will be noted that the idea throughout has been
to make it possible to replace all the ordinary
arrangements very quickly, and to make the ex-
periments without damaging the ordinary ac-
tion at all. Hence the device of the intermedi-
ate blocks between governor or box and bel-
lows, etc. Any imaginable refinement may be
made, of course.]
The power-plant is simply a small one-eighth
horsepower motor driving by a belt and driving
wheel, a double pumping bellows, through a
shaft and cranks. A rotary blower can be had
if desired and there are several pumping units
on the market. The writer used the first thing
that came to hand; namely, the pumping set of
a coin-operated action model. This includes an
equalizer unit, which has a relief-valve, so that
if the equalizer closes to a certain point, the
valve opens and admits atmospheric pressure.
This is a simple and effective safety device.
Downstairs
In the experiments which form the basis of
these remarks, the pumping device, for conve-
nience sake and to save possible noise and
complication, not to mention appearance, was
left downstairs in the basement, and a suction
pipe run up through the floor to the point where
the various suction tubes from the elements were
assembled. The pipe is invisible and interferes
(Continued an page 8)
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