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THE MUSIC TRADE REVIEW
9
The Possibilities of Dynamic Reproduction in the Player-Piano Have Just
Begun to Be Investigated, and a Fascinating Field for Practical Development
Awaits Experimenter Devising Means for Registering Hammer Velocity
The extraordinary commercial success which
has greeted the more prominent efforts at pro-
ducing a complete record of artist's playing
should not blind one's eyes to the existence of
serious technical problems, the complete solu-
tion of which is to be found only in the future.
It is neither nscessary nor desirable to consider
whether the present reproduction systems are
entirely adequate, or how far they satisfy the
elements of the theoretical problem. It is
enough for us to know that, as a technical prob-
lem and as such only, the whole idea of player
reproduction offers a field for research com-
pared with which almost any other within the
realm of musical technology pales into insig-
nificance.
In the present article we wish to consider
the possibilities at present existing of an attack
on one side of the reproduction problem, a side
equally fascinating and recondite. For want of
a better term we may call this the problem of
direct dynamic registration.
To put it in less concise but more simple
terms, the problem which we wish briefly to
notice is that of directly registering, by means
afterwards translatable efficiently on the roll,
the intensities of sound produced from moment
to moment by the pianist, whether as to any
single tone, as to simultaneous groups, or as to
successive chord and group elements. We wish
to say at the outset that we shall not consider
any existing method of reproduction, and shall
have nothing to say either as to the claims or as
to the basis for the claims, of any existing sys-
tem. What we have to say is concerned with
a line of research useful to all but so far not
put into mechanical shape by anybody.
This article therefore is in no sense critical,
directly or indirectly; but it is explanatory and
suggestive only.
A Postponed Agreement
It may be set down as a fact not without its
significance that the scientific and musical world
is coming around pretty rapidly to the conclu-
sion that all which the pianist does by means
of his "touch" is dependent upon, and may be
stated in terms of, hammer velocity. In short,
it is now recognized by the highest authorities
that control of tone is control of hammer-speed,
and no more or less than this. Now, in point
of fact, the whole question thus involved was
stated, analyzed and worked out in this paper
by the present writer some live years ago, as
may be found by the simple process of referring
to the back numbers. From time to time since,
additional statements of the matter have been
made in these columns. We know not that it
is of much importance to our present purpose,
but we cannot resist observing that a contem-
porary, in a recent discussion of the reproduc-
ing piano, after quoting a well known musician,
gravely announces the discovery that tone-con-
trol is due to hammer-velocity control; and then
goes on to hope that we shall all hasten to
acquaint ourselves with this conclusion, adding
that the subject has never before been handled
by any one else, since no one else (at least
among piano trade papers) could by any chance
be considered capable of understanding the
questions involved. Yet, that very subject was
analyzed and the problem solved by the present
writer some five years ago and has formed the
basis of perhaps a dozen later articles from his
pen since! Incidentally, it may be further
observed that the entire matter, essential as it
is, has been quite pointedly ignored by musical
and technical men until very recently.
It is, however, sufficient for the present pur-
pose to point out that, in his latest work (Sci-
ence of Musical Sounds, 1916), Dr. Dayton Mil-
ler, who is without doubt the first of American,
acousticians and whose research work in tone-
analysis has been far more complete than his
predecessors ever dreamed might be possible,
says positively: "Having investigated this ques-
tion with ample facilities, we are compelled by
the definite results to say that, if tones of the
same loudness are produced by striking the keys
of a piano with a variety of touches, the tones
are always and necessarily of identical quality;
or, in other words, a variation of artistic touch
cannot produce a variation of tone quality from
one key, if the resulting tones are all of the
same loudness."
Loudness and Hammer-Blow
Now this statement is sufficiently definite and,
besides, is confirmed amply in the body of the
work. But we may go a step further. Loudness,
as has been shown in the work quoted, and as
is well known, depends mechanically upon the
speed of the hammer-blow. The more forcible
key-blow means a correspondingly rapid ham-
mer-travel and consequently a correspondingly
forcible hammer-blow. Tone-control is ham-
mer-speed-control; no more and no less. It is
this fact which the present writer has been
arguing for several years back.
To come back to our original problem, the
registration of dynamics would seem, therefore,
to condense itself into registration of hammer
velocities. Is it possible to register the speed of
the hammer-travel in any way mechanically
efficient for reproduction through the agency of
the music-roll?
A Direct Attack
If we attack directly this complex problem
it is obvious that we could begin by taking a
large number of films of the sound-waves gen-
erated in piano playing, by means of Dr.
Miller's Phonodeik. With this instrument it is
possible to obtain an accurate visible record of
the oscillations af a diaphragm upon which the
sound-waves proceeding from a musical instru-
ment impinge. The comparative loudness or
softness of each sound is proportionally repre-
sented by the amplitudes or widths of swing of
the vibrating strings or other media, and these
changing amplitudes are shown faithfully by the
Phonodeik.
If now the oscillations of the
Phonodeik's mirror are photographed by means
of a special motion picture camera, as Dr. Mil-
ler has done in many other cases, and if a
sufficient number of such photographs are taken,
it is obvious that we can obtain data sufficient
to enable us to frame certain standards by which
to judge the significance of all such records in
the future. For instance, when enough data
have been accumulated we shall find that, allow-
ing for all incidental variations, a certain lim-
ited number of what may be called amplitude-
graphs correspond to all the general intensities
of tone generated by pianists. In other words,
from the mass of sound-wave-pictures obtained,
we shall certainly find certain definite widths or
amplitudes emerging more frequently than
others, and in course of time we might average
these and obtain a limited number of standard
amplitudes of wave, corresponding to an equal
number of loudnesses of sound. Thus a loud-
ness scale may be drawn up and any future
Phonodeik record compared with it. Thus also,
although the mechanical features of the problem
are not to be dismissed lightly, it would be pos-
sible to work out a corresponding set of ex-
pression governor spring-tensions, so that the
expression perforations on the roll might be
marked in strict accordance with the amplitude
scale; and thus a parallel to the dynamics of
the original performance be obtained.
Velocity-Registration
If this method be regarded as too difficult,
the next one would be that which attempts to
register the velocity of the hammer. It is
obvious that there are several ways in which
this might be done. The most obvious are, of
course, electrical. The hammer can be made to
close a circuit upon starting its travel and to
open it again on touching the string. Or the
reverse might be the method of operation. In
either case it is plain to see that by using a
make-and-break of circuit like this, a record on
moving sheet may be obtained, longer or shorter
according to the hammer-speed. A machine
would have to be devised by means of which a
trace should be begun on a moving sheet at the
moment of beginning each hammer-stroke, and
stopped at the moment of contact with the
string. The thing is obviously possible as soon
as the mechanical requirements have been defi-
nitely stated. There already exist several in-
struments for time marking which can be used
if necessary as a basis for experimentation.
The problem in this shape is respectfully sub-
mitted to the consideration of Martin New-
comer and that of the Phonodeik record to the
distinguished physicist who conceived and per-
fected that unique instrument.
There remains one other possibility. It is
within the range of mechanical conceivability
that an instrument should be devised for regis-
tering the intensity of pressure on piano keys.
There are several possible ways of doing this.
Perhaps the most obvious would be to cause
the key to overcome a series of progressive re-
sistances, which might be used to vary the
strength of a current flowing through a circuit.
But there is, of course, the possibility of unduly
disturbing the practical touch of the keyboard
and the greatest care would have to be exer-
cised in order to avoid difficulties here. The
fact is that experimentation on the keys would
very likely drive the experimenter away from
trying to register resistance, and force him into
registering speed; which would simply be to do
less efficiently what has already been suggested
as concerns the hammer itself. On the whole
we are inclined to the belief that intensity-
registration, as we may call it, will have to be
done either through the graphic representation
made possible by the Phonodeik or through the
registration of hammer-velocities. That there
is in this respect an enormously interesting and
valuable field for experiment no one will deny.
That great things are to be expected of such
experiments no one will deny either. The art
of reproducing the playing of musical instru-
ments of itself offers a field for research suffi-
ciently fascinating, but it may also be observed
that an incidental and almost equally valuable
point will be found in the addition to general
knowledge of the phenomena of tone-production
which such research must inevitably produce.
There is not much doubt that the next few
years will see the player-piano field sharply
divided into two camps. One will be concerned
with the refinement and perfecting of the repro-
ducing piano. The other will be equally de-
voted to the personally controlled instrument.
Both are as yet in their infancy. Both are
capable of almost endless development. We are
endeavoring to do something to assist each.