Music Trade Review
Issue: 1923 Vol. 76 N. 4 - Page 9
Music Trade Review -- © mbsi.org, arcade-museum.com -- digitized with support from namm.org
JANUARY 27,
1923
THE MUSIC TRADE REVIEW
9
jjjaiKsaifeai&sgi&iai&aitii^
Some Fundamental Principles]; of Automatic Expression—Reproduction' of
Dynamic Variations the Essential Factor in the Seven Embodied in the
Performance of Any Musical Composition—Crux of the Entire Problem
Despite, or perhaps on account of the very
rapid growth of the automatic expression player-
piano in trade importance, there seems to exist
a good deal of misapprehension as to the prin-
ciples on which are founded all mechanical reali-
zations of the idea. In view of the general con-
fusion which continues to persist in the use of
the phrase "reproducing piano," the alternative
term "automatic expression player-piano" will
be used for the purposes of the present article.
There is also another reason for doing this. All
instruments which do not depend upon the
intervening volition of a human player-pianist
for the expressiveness of their music are com-
prehended within the natural scope of the term
"automatic expression." On the other hand, the
term "reproducing piano" is not inclusive, but
rather represents a particular development only
of automatic expression principles. All repro-
ducing pianos, in other words, are automatic
expression pianos; but all automatic expression
pianos are not reproducing pianos. For a full
discussion of this subject in all its bearings the
reader is referred to the columns of the Player
Section in issues of this paper of some twelve
months ago. The matter was there analyzed
completely, and certain definitions were pro-
posed which, if adopted and adhered to, would
completely abolish the existing confusion. It
is therefore unnecessary to refer to the matter
again in this place.
Factors of Performance
On the other hand, it is very necessary to
put before the reader in a fundamental sort of
way the factors of musical performance which
the art of automatic expression is designed to
realize mechanically. We have to ask ourselves,
in fact, if ever we are to understand the mechan-
ical peculiarities of the automatic expression in-
struments, into what elements can the art of
musical expression be resolved, and how do
they appear to the pneumatic engineer who
desires to record them as realized in the play-
ing of an artist or in the general consent of
musicians.
If we consider the performance of any piece
of music upon the piano we find that it resolves
itself into the complex interrelations of several
simple elements. These elements can be de-
scribed in this way:
1. Selection of the proper sounds.
2. Evocation of these sounds in their due
order.
3.—Duration of each sound, both as consid-
ered in itself and as related to preceding, simul-
taneous and succeeding sounds.
4. Comparative loudness of each tone as con-
trolled by finger contact with the keys of the
piano.
5. Comparative loudness as affected by the
pianist's manipulation of the pedals.
6. Tone-quality as affected b y the tactual
manipulation of the hammers through the keys.
7. Tone quality as affected by the manipula-
tion of the pedals by the pianist.
Within these seven divisions can be found
a place for all the commonly received divisions,
such as phrasing, speed, "touch," etc., all of
which are ambiguous, and at least one of which
is habitually used by musicians in the most
confusing manner. Of course, it is plainly
understood that the very term "automatic ex-
pression" implies "automatic duplication of fac-
tors previously determined by human volition."
The artist is always behind, whether one or two
steps in the rear.
Now, in the list of seven factors which is
set forth above, it is easy to see that, no matter
what method of recording be used, the first
three factors are immediately realized when the
music roll has been produced from the record
made by the pianist. But since there exists
(or, at least, is in use) no practical way of re-
cording the mechanical velocity of the hammer
which determines the sound-effect produced by
the string, all methods for obtaining the nearest
possible reproduction of the fourth and sixth
factors in the above list must be obtained by
a process of indirection which, however, need
not thereby be the less efficient in the final
result.
In fact, the whole realization of automatic
expression turns upon the principles adopted
in dealing with factor No, 4 in particular. Nos.
5 and 7 can very easily be recorded, since they
depend upon certain simple mechanical motions
imparted to the mechanism of the piano by the
feet of the pianist. It is obvious that such
motions can be recorded by pencil tracings, just
as the key-contacts of the pianist are simul-
taneously recorded on the moving record sheet.
On the other hand, the dynamic reproduction
must be approached by indirection.
Dynamics and Air Pressure
As we all know, all dynamic variation is a
function of the working pressure of the player
mechanism. This working pressure depends
upon the difference between the fixed atmos-
pheric pressure and the continually variable in-
ternal pressure. In the foot-controlled player
the variable internal pressure depends upon the
direct mechanical action of the player-pianist's
feet upon the pedals which control the bellows.
It may also depend upon pneumatic reducing
valves, controllable either entirely by the player-
pianist or partly by him and partly by making
use of the motion of the paper across the
tracker-bar to throw the valves into or out of
operation by means of suitable perforations in
the paper corresponding with ducts in the
tracker-bar. If the editor of the music roll
places perforations in the. margin of the roll
opposite the note perforations which he desires
to affect as to dynamic power, by subjecting
them to the action upon the air pressure of the
reducing valves, he can modify the dynamics of
the playing and to that extent control the ex-
pression. This can be done so that the player-
pianist cannot change the effects by his pump-
ing, or again when the player-pianist .is elimi-
nated and a power pumping plant substituted,
this system can be expanded until all the
dynamic powers are controlled in this manner
By continually expanding this principle, an>
breadth of control over dynamics can be at-
tained. It all comes to (1) the skill of the
musician who determines how the governing
equipment of reducing valves shall be used;
(2) the number of such valves; (3) the mechani-
cal efficiency of the control exerted by the
(Continued on page 10)
Every player-piano owner is a prospect for this beautiful
roll cabinet. It doesn't require selling. Merely show it.
The profit possibilities of these beautiful Udell console
cabinets are unlimited. Sell what your customers want
and make your profit—quickly, easily, surely.
The UDELL WORKS
::
28th St. and Barnes Avenue
Indianapolis
JANUARY 27,
1923
THE MUSIC TRADE REVIEW
9
jjjaiKsaifeai&sgi&iai&aitii^
Some Fundamental Principles]; of Automatic Expression—Reproduction' of
Dynamic Variations the Essential Factor in the Seven Embodied in the
Performance of Any Musical Composition—Crux of the Entire Problem
Despite, or perhaps on account of the very
rapid growth of the automatic expression player-
piano in trade importance, there seems to exist
a good deal of misapprehension as to the prin-
ciples on which are founded all mechanical reali-
zations of the idea. In view of the general con-
fusion which continues to persist in the use of
the phrase "reproducing piano," the alternative
term "automatic expression player-piano" will
be used for the purposes of the present article.
There is also another reason for doing this. All
instruments which do not depend upon the
intervening volition of a human player-pianist
for the expressiveness of their music are com-
prehended within the natural scope of the term
"automatic expression." On the other hand, the
term "reproducing piano" is not inclusive, but
rather represents a particular development only
of automatic expression principles. All repro-
ducing pianos, in other words, are automatic
expression pianos; but all automatic expression
pianos are not reproducing pianos. For a full
discussion of this subject in all its bearings the
reader is referred to the columns of the Player
Section in issues of this paper of some twelve
months ago. The matter was there analyzed
completely, and certain definitions were pro-
posed which, if adopted and adhered to, would
completely abolish the existing confusion. It
is therefore unnecessary to refer to the matter
again in this place.
Factors of Performance
On the other hand, it is very necessary to
put before the reader in a fundamental sort of
way the factors of musical performance which
the art of automatic expression is designed to
realize mechanically. We have to ask ourselves,
in fact, if ever we are to understand the mechan-
ical peculiarities of the automatic expression in-
struments, into what elements can the art of
musical expression be resolved, and how do
they appear to the pneumatic engineer who
desires to record them as realized in the play-
ing of an artist or in the general consent of
musicians.
If we consider the performance of any piece
of music upon the piano we find that it resolves
itself into the complex interrelations of several
simple elements. These elements can be de-
scribed in this way:
1. Selection of the proper sounds.
2. Evocation of these sounds in their due
order.
3.—Duration of each sound, both as consid-
ered in itself and as related to preceding, simul-
taneous and succeeding sounds.
4. Comparative loudness of each tone as con-
trolled by finger contact with the keys of the
piano.
5. Comparative loudness as affected by the
pianist's manipulation of the pedals.
6. Tone-quality as affected b y the tactual
manipulation of the hammers through the keys.
7. Tone quality as affected by the manipula-
tion of the pedals by the pianist.
Within these seven divisions can be found
a place for all the commonly received divisions,
such as phrasing, speed, "touch," etc., all of
which are ambiguous, and at least one of which
is habitually used by musicians in the most
confusing manner. Of course, it is plainly
understood that the very term "automatic ex-
pression" implies "automatic duplication of fac-
tors previously determined by human volition."
The artist is always behind, whether one or two
steps in the rear.
Now, in the list of seven factors which is
set forth above, it is easy to see that, no matter
what method of recording be used, the first
three factors are immediately realized when the
music roll has been produced from the record
made by the pianist. But since there exists
(or, at least, is in use) no practical way of re-
cording the mechanical velocity of the hammer
which determines the sound-effect produced by
the string, all methods for obtaining the nearest
possible reproduction of the fourth and sixth
factors in the above list must be obtained by
a process of indirection which, however, need
not thereby be the less efficient in the final
result.
In fact, the whole realization of automatic
expression turns upon the principles adopted
in dealing with factor No, 4 in particular. Nos.
5 and 7 can very easily be recorded, since they
depend upon certain simple mechanical motions
imparted to the mechanism of the piano by the
feet of the pianist. It is obvious that such
motions can be recorded by pencil tracings, just
as the key-contacts of the pianist are simul-
taneously recorded on the moving record sheet.
On the other hand, the dynamic reproduction
must be approached by indirection.
Dynamics and Air Pressure
As we all know, all dynamic variation is a
function of the working pressure of the player
mechanism. This working pressure depends
upon the difference between the fixed atmos-
pheric pressure and the continually variable in-
ternal pressure. In the foot-controlled player
the variable internal pressure depends upon the
direct mechanical action of the player-pianist's
feet upon the pedals which control the bellows.
It may also depend upon pneumatic reducing
valves, controllable either entirely by the player-
pianist or partly by him and partly by making
use of the motion of the paper across the
tracker-bar to throw the valves into or out of
operation by means of suitable perforations in
the paper corresponding with ducts in the
tracker-bar. If the editor of the music roll
places perforations in the. margin of the roll
opposite the note perforations which he desires
to affect as to dynamic power, by subjecting
them to the action upon the air pressure of the
reducing valves, he can modify the dynamics of
the playing and to that extent control the ex-
pression. This can be done so that the player-
pianist cannot change the effects by his pump-
ing, or again when the player-pianist .is elimi-
nated and a power pumping plant substituted,
this system can be expanded until all the
dynamic powers are controlled in this manner
By continually expanding this principle, an>
breadth of control over dynamics can be at-
tained. It all comes to (1) the skill of the
musician who determines how the governing
equipment of reducing valves shall be used;
(2) the number of such valves; (3) the mechani-
cal efficiency of the control exerted by the
(Continued on page 10)
Every player-piano owner is a prospect for this beautiful
roll cabinet. It doesn't require selling. Merely show it.
The profit possibilities of these beautiful Udell console
cabinets are unlimited. Sell what your customers want
and make your profit—quickly, easily, surely.
The UDELL WORKS
::
28th St. and Barnes Avenue
Indianapolis
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