MEANS OF OBTAINING EXPRESSION.
CRESCENDO PEDAL.
To most organs in this country, to many in Germany, and to a few in
other countries, there is attached a balanced shoe pedal by movement of
which the various stops and couplers in the organ are brought into
action in due sequence. By this means an organist is enabled to build
up the tone of his organ from the softest to the loudest without having
to touch a single stop-knob, coupler or combination piston. The
crescendo pedal, as it is called, is little used in England. It is the
fashion there to regard it merely as a device to help an incompetent
organist. It is contended that a crescendo pedal is most inartistic,
as it is certain to be throwing on or taking off stops in the middle,
instead of at the beginning or end of a musical phrase. In spite of
this acknowledged defect, many of the best players in this country
regard it as a legitimate and helpful device.
We believe the first balanced crescendo pedal in this country was put
in the First Presbyterian Church organ at Syracuse, N. Y., by Steere,
the builder of the instrument.
SFORZANDO PEDAL--DOUBLE TOUCH.
Under the name of Sforzando Coupler, the mechanism of which is
described and illustrated in Stainer's Dictionary, a device was
formerly found in some organs by which the keys of the Swell were
caused to act upon the keys of the Great. The coupler being brought on
and off by a pedal, sforzando effects could be produced, or the first
beat in cadi measure strongly accented in the style of the
orchestration of the great masters. Hope-Jones in his pioneer organ at
St. John's Church, Birkenhead, England, provided a pedal which brought
the Tuba on the Great organ. The pedal was thrown back by a spring on
being released from the pressure of the foot. Some fine effects could
be produced by this, but of course the whole keyboard was affected and
only chords could be played. Various complicated devices to bring out
a melody have been invented from time to time by various builders, but
all have been superseded by the invention of the "Double Touch." On a
keyboard provided with this device, extra pressure of the fingers
causes the keys struck to fall an additional eighth inch (through a
spring giving way), bringing the stops drawn on another manual into
play. If playing on the Swell organ, the Choir stops will sound as
well when the keys are struck with extra firmness; if playing on the
Choir the Swell stops sound; and if playing on the Great the Double
Touch usually brings on the Tuba or Trumpet. It is thus possible to
play a hymn tune in four parts on the Swell and bring out the melody on
the Choir Clarinet; to play on the Choir and bring out the melody on
the Swell Vox Humana or Cornopean; or to play a fugue with the full
power of the Great organ (except the Trumpet) and bring out the subject
of the fugue every time it enters, whether in the soprano voice, the
alto, tenor, or bass.
In the latest Hope-Jones organs arrangements are made for drawing many
of the individual stops on the second touch, independently of the
couplers.
BALANCED SWELL PEDAL
At the commencement of the period of which we are treating (some fifty
years ago) the Swell shutters of almost all organs were made to fall
shut of their own weight, or by means of a spring. The organist might
leave his Swell-box shut or, by means of a catch on the pedal, hitch it
full open.
When, however, he wanted the shutters in any intermediate position, he
had to keep his foot on the pedal in order to prevent its closing.
The introduction of the balanced Swell pedal (Walcker, 1863) has
greatly increased the tonal resources of the organ. It is used almost
universally in this country, but strangely enough the country in which
the Swell-box was invented (England, 1712) lags behind, and even to-day
largely adheres to the old forms of spring pedal.
A further and great step in advance appears in recent organs built by
the Hope-Jones Organ Company. The position of the swell shutters is
brought under the control of the organist's fingers as well as his
feet. Each balanced swell pedal is provided with an indicator key
fixed on the under side of the ledge of the music desk, where it is
most conspicuous to the eye of the performer. As the swell pedal is
opened by the organist's foot, the indicator key travels in a downward
direction to the extent of perhaps one inch and a quarter. As the
organist closes his pedal, the indicator key again moves upward into
its normal position. By means of this visible indicator key the
organist is always aware of the position of the swell shutters.
Through electric mechanism the indicator key is so connected with the
swell pedal that the slightest urging of the key either upward or
downward by the finger will shift the swell pedal and cause it to close
or open as may be desired and to the desired extent. When an organ
possesses four or five swell boxes, and when these swell boxes (as in
the case of Hope-Jones' organs) modify the tone by many hundred per
cent., it becomes highly important that the organist shall at all times
have complete and instant control of the swell shutters and shall be
conscious of their position without having to look below the keyboards.
Hope-Jones also provides what he calls a general swell pedal. To this
general swell pedal (and its corresponding indicator key) any or all of
the other swell pedals may be coupled at will.
Hope-Jones has also recently invented a means of controlling the swell
shutters from the manual keys to a sufficient extent to produce certain
sforzando effects.
When this contrivance is brought into use upon any manual and when no
keys upon that manual are being played, the swell shutters assume a
position slightly more open than normal in relation to the position of
the swell pedal. Directly any key upon the manual in question is
depressed, the swell shutters again resume their normal position in
relation to the swell pedal. This results in a certain emphasis or
attack at the commencement of each phrase or note that is akin to the
effect obtained from many of the instruments of the orchestra.
These contrivances are applicable only to such organs as have the
balanced swell pedal.
SWELL BOXES.
The invention of the Swell is generally attributed to Abraham Jordan.
He exhibited what was known as the nag's head Swell in St. Magnus'
Church, London, England, in the year 1731.
The "nag's head" Swell, with its great sliding shutter, rapidly gave
place to the "Venetian" Swell shades, used almost universally to this
day. At the beginning of the period under consideration Swell boxes
were almost invariably made of thin boards and their effect upon the
strength of the tone was small. Willis was one of the first to realize
the artistic possibilities of the Swell organ and in almost all his
organs we find thick wooden boxes and carefully fitted shutters, and
often an inner swell box containing the delicate reeds, such as the Vox
Humana and Oboe.
Many of the leading organ builders now employ this thicker
construction, and it is no uncommon thing to find Swell boxes measuring
three inches in thickness and "deadened" with sawdust or shavings
between the layers of wood of which they are formed.
A few organs of Hutchings and other makers are provided with a double
set of shutters, so that sound waves escaping through the first set are
largely arrested by the second. The _crescendo_ and _diminuendo_ are
thus somewhat improved.
By the adoption of scientific principles Hope-Jones has multiplied the
efficiency of Swell boxes tenfold. He points out that wood, hitherto
used in their construction, is one of the best known conductors of
sound and should, therefore, not be employed. The effects produced by
his brick, stone and cement boxes (Worcester Cathedral, England; McEwan
Hall, Edinburgh, Scotland, Ocean Grove, New Jersey, etc.) mark the dawn
of a new era in Swell-box construction and effect. It is now possible
to produce by means of scientific Swell boxes an increase or diminution
of tone amounting to many hundred per cent.
We have heard the great Tuba at Ocean Grove, on 50-inch wind pressure,
so reduced in strength that it formed an effective accompaniment to the
tones of a single voice.
The Hope-Jones method seems to be to construct the box and its shutters
(in laminated form) of brick, cement or other inert and non-porous
material, and to substitute for the felt usually employed at the joints
his patented "sound trap." This latter is so interesting and of such
import in the history of organ building that we append, on the next
page, illustrations and descriptions of the device.
If a man should stand at one end of the closed passage (C) he will be
able to converse with a friend at the other end of the passage (D).
The passage will in fact act as a large speaking tube and a
conversation can be carried on between the two individuals, even in
whispers (Figure 12).
This passage is analogous to the opening or nick between Swell shutters
of the ordinary type.
If a man should stand in room 1 at A, he will be able to see a friend
standing in room 4 at B, but the two friends will not be able to
converse. When A speaks, the sound waves that he produces will spread
out and will fill room 1. A very small percentage of them will strike
the doorway or opening into room 2. In their turn these sound waves
will be diffused all through room 2, and again but a small percentage
of them will find access into room 3. The sound waves will by this
time be so much attenuated that the voice of the man standing in room 1
will be lost. Any little tone, however, that may remain will become
dissipated in room 3, and it will not be possible for a person standing
in room 4 to hear the voice.
[Illustration: Fig. 12. The Principle of the Sound Trap]
This plan illustrates the principle of the sound trap joint.
Figure 13 shows in section the joint between two Swell shutters. A
small proportion of the sound waves from inside the Swell box striking
the sound trap joint, as indicated by the arrow, will pass through the
nick between the two shutters, but these sound waves will become
greatly weakened in charging the groove A. Such of the sound waves is
pass through the second nick will become attenuated in charging the
chamber B. They will be further lost in the chamber C, and practically
none will remain by the time the chamber D is reached.
It is Hope-Jones' habit to place the shutters immediately above the
pipes themselves, so that when they are opened the Swell box is left
practically without any top. It is in such cases not his custom to fit
any shutters in the side or front of the Swell box.
[Illustration: Fig. 13. Sound Trap Joint]
To relieve the compression of the air caused by playing for any length
of time with the shutters closed, he provides escape valves, opening
outside the auditorium. He also provides fans for driving all the cold
air out of the box before using the organ, thus equalizing the
temperature with the air outside--or he accomplishes this result
through the medium of gas, electric or steam heaters, governed by
thermostats.
The Hope-Jones Vacuum Swell Shutters, with sound-trap joints, are shown
in Figures 14 and 15.
It is well known that sound requires some medium to carry it. Readers
will doubtless be familiar with the well-known experiment illustrating
this point. An electric bell is placed under a glass dome. So long as
the dome is filled with air the sound of the bell can be heard, but
directly the air is pumped out silence results, even though it can be
seen that the bell is continuously ringing. As there is no air
surrounding the bell there is nothing to convey its vibrations to the
ear.
That is why the hollow swell shutter, from the interior of which the
air has been pumped out, is such a wonderful non-conductor of sound.
The shutters shown in Figures 14 and 15 are aluminum castings.
Ribs R|1| and R|2| are provided to support the flat sides against the
pressure of the atmosphere, but each of these ribs is so arranged that
it supports only one flat side and does not form a means of
communication between one flat side and the other. Thus R|1| supports
one flat side whilst R|2| supports the other. The aluminum shutters
are supported by means of pivot P.
[Illustration: Figs. 14-15. The Vacuum Shutter]
They are very light and can therefore be opened and closed with great
rapidity.
A very thin vacuum shutter forms a better interrupter of sound waves
than a brick wall two or three feet in thickness.
When partially exhausted the aluminum shutters are dipped into a bath
of shellac. This effectually closes any microscopic blow-hole that may
exist in the metal.
The use of Swell boxes of this vastly increased efficiency permits the
employment of larger scales and heavier pressures for the pipes than
could otherwise be used, and enormously increases the tonal flexibility
of the organ.
It also does away with the need for soft stops in an organ, thus
securing considerable economy. Where all the stops are inclosed in
cement chambers (as in the case of recent Hope-Jones organs) and where
the sound-trap shutters are employed, _every_ stop is potentially a
soft stop.