Music Trade Review

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THE MUSIC TRADE REVIEW
11
Certain Pneumatic Aspects of Tempo Control Discussed—The Real Im-
portance of the Player Motor and Its Functions—Deserves More Real
Attention Than It Has Received—The Necessity of Motor Flexibility.
Without much danger of appearing to cross any-
body's opinions, we may assume that in some form
or another the player-piano industry is definitely
committed to the pneumatic motor for driving the
perforated roll across the tracker. But to be com-
mitted to an idea is one thing, and to have made
the idea perfect is quite another. The general sub-
ject of motor requirements, including the im-
mensely important topic of tempo control, ^ has
rather been permitted to follow its own course, and
in consequence there has been little or nothing
done in the way of systematizing our ideas on the
matter. Yet nothing is more important to a due
understanding of what constitutes good construc-
tional practice than this matter.of the motor, its
functions and its design.
The great and overshadowing requirement for a
player-motor is, necessarily, flexibility. Enough
power can be had from any number of different
prime sources, nor is there any difficulty in apply-
ing all sorts of methods to the mere task of
winding a paper roll of from twenty to one hun-
dred feet in length on to one spool and off another.
If no more were needed than the provision of such
power and its application at given pre-determined
constant velocities, this article would not require
to be written. But things are not in such a happy
condition.
Prime Pre-requisite Is Flexibility.
The prime pre-requisite of player-piano inter-
pretation is flexibility of tempo. Whatever may in
the past have been believed on this subject, no
sane man now attempts to deny that this one qual-
ity is essential, nor that without it the finest prime
mover would be without value in the art of player
building. Nevertheless, the fact remains that all
the possibilities inherent in this word "flexibility"
have by no means been exhausted by player de-
signers.
The mechanical functions of the player motor
are two in number. The first is the obvious duty
Quality
Hardware
for
Piano and Player
Actions
The Blake & Johnson Co.
Waterbury, Conn.
Since 1849
of driving the spooled paper over the tracker. The
second is the less obvious but equally important
duty of responding to any and all demands of the
performer for changes of speed. These changes
must be made as rapidly as required and to any
extent. The motor cannot be, on the one hand,
too nearly steady at a given speed, nor, on the
other hand, too responsive to change in that speed.
This idea of responsiveness is therefore rightly
to be regarded as the characteristic idea of the
player motor. The mechanical methods which have
been adopted for carrying it out, however, are
not at all as advanced as the conception has come
to be. In other words, our notions of what a
motor ought to do are ahead of our mechanical
means for getting the results we demand. Let
us examine this point.
Delicate Nature of the Motor.
Any form of pneumatic motor so far developed
should be capable of surprisingly delicate changes
in speed for the simple reason that the air itself,
which is the source of power, is so flexible. The
whole atmosphere is one vast sea, at the bottom
of which we exist, and the displacement anywhere
of any quantity of this atmosphere, however small,
from its original position, necessarily affects the
whole body. Thus, the displacement of some air
trom the inside of a player motor produces a
corresponding effective pressure, which is instan-
taneously generated, and equally rapidly changed
as the given activity of displacement from moment
to moment changes. It is just like putting one's
finger against a great hollow rubber ball. The
slightest pressure on the outside of the ball pro-
duces corresponding compression of the air inside.
If the ball were so delicately made that its walls
did not resist the air pressure, then the inside air
would expand in one direction whenever it was
compressed from the outside in another. So it
is, to speak roughly, with the atmosphere. Per-
vaded by, and swimming in the atmospheric ocean
as it were, all objects on the earth's surface re-
spond instantly to any change in its normal pres-
sure. Hence the responsiveness of the pneumatic
motor is of high degree, and furnishes this type
with a true title to the highest utility for the
purposes of the player-piano.
But while this is all true, it is also true that,
generally speaking, the mechanical means for con-
trolling the atmospheric pressure changes are by
no means of the highest utility. If we consider
the ordinary tempo-valve of the player motor we
see that it is a direct descendant of the throttle
of the steam engine, and a contemporary of the
throttle in the gasoline carburetor. It is, in short,
what at one time we always called it, a "gate."
But it will generally be admitted, one hopes, that
the gate form of tempo control is a crude thing.
It is essentially the same to-day as it was when
the first cabinet players were put out. Those ma-
chines were experimental. Nobody knew just how
they would work, or in what direction they would
develop. Especially, nobody knew that they would
ever require as a prime requisite the utmost flexi-
bility of motor control. And so the gate was
good enough for them. But it is not good enough
to-day. And why?
Music That Calls for Motor Flexibility. -
Simply because to-day we want to make instant
changes from the highest speed to the lowest, and
conversely. Let us give a concrete example. Take
the piano concerto of Schumann. Go and hear
some great pianist play it with the accompaniment
of a great orchestra, if you can. Then take the
,roll of its second movement and see whether, with
anything short of the most flexible motor control,
you can imitate the manner in which that pianist
phrases the opening chords of the intermezzo. A
master player-pianist can do it. But the amateur
will find he has to work hard to get the thing at
all. For here is a case where the requirement is
to play a series of pianissimo chords semi-staccato,
with a partially complete detachment or interval
between each pair, and with a phrasing that di-
vides up the series into groups of four, with a
marked interval between each group. The roll has .
the chords all set forth in regular order, at equal
distances from each other, so that the process of
playing them in strict time would lead to stiffness
and "mechanicalness" intolerable. Here is needed
the very best kind of responsiveness. And the
only way to get it, with the usual type of control,
is to cultivate great alertness of wrist and hand,
so that the tempo lever may be moved back and
forth over its long travel from zero to 130 so
lightly, quickly and securely that the chords shall
come tripping out just as they would fall from the
fingers of a Hoffmann or a Sauer. It can be done;
but not easily.
Of course it will be said here that the hand-
played roll abolishes all necessity for this sort of
thing. So it would if we could simultaneously
abolish all non-hand-played rolls. But we cannot,
and we do not wish to. The player is perhaps
almost enough of a self-player as it is. What we
want is greater motor flexibility.
How to Get Relief.
How can we get it? Well, for one thing, we
need a new form of valve. The Angelus phrasing
(Continued on page 12.)
^ j L
RTEMPO
Music Rolls are NEW;
they reproduce the ac-
tual interpretation of the artist
without the use of expression
levers.
Individual expression
may also be used if desired.
Can be used on all 88-note player-
pianos. We specialize in the produc-
tion of hand-played music roll records
and offer a service that is bound to
increase the sales and satisfaction of
your player-piano clientele.
Send for a sample Ar tempo roll and
prove that this roll is of exceptional
merit.
Bennett & White, Inc.
54 Austin Street
Newark, N. J.