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.

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. Thecrescendoanddiminuendoare 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.

Fig. 12. The Principle of the Sound TrapFig. 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.

Fig. 13. Sound Trap JointFig. 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 R1and R2are 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 R1supports one flat side whilst R2supports the other. The aluminum shutters are supported by means of pivot P.

Figs. 14-15. The Vacuum ShutterFigs. 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,everystop is potentially a soft stop.

Prior to the construction of the above-named organ at Birkenhead, England, it had been the custom to obtain or regulate the pressure of wind supplied to the pipes by means of loading the bellows with weights. Owing to its inertia, no heavy bellows weight can be set into motion rapidly. When, therefore, a staccato chord was struck on one of these earlier organs, with all its stops drawn, little or no response was obtained from the pipes, because the wind-chest was instantly exhausted and no time was allowed for the inert bellows weights to fall and so force a fresh supply of air into the wind-chests.

In one of Hope-Jones' earliest patents the weights indeed remain, but they merely serve to compress springs, which in turn, act upon the top of the bellows.

Before this patent was granted he had, however, given up the use of weights altogether and relied entirely upon springs.

This one detail—the substitution of springs for weights—has had a far-reaching effect upon organ music. It rendered possible the entire removal of the old unsteadiness of wind from which all organs of the time suffered in greater or less degree. It quickened the attack of the action and the speech of the pipes to an amazing extent and opened a new and wider field to the King of Instruments.

In the year 1894 John Turnell Austin, now of Hartford, Conn., took out a patent for an arrangement known as the "Universal air-chest." In this, the spring as opposed to the weight is adopted. The Universal air-chest forms a perfect solution of the problem of supplying prompt and steady wind-pressure, but as practically the same effect is obtained by the use of a little spring reservoir not one hundredth part of its size, it is questionable whether this Universal air-chest, carrying, as it does, certain disadvantages, will survive.

Fifty years ago the pallet and slider sound-board was well nigh universally used, but several of the builders in Germany, and Roosevelt in this country, strongly advocated, and introduced, chests having an independent valve, pallet or membrane, to control the admission of wind to each pipe in the organ.[1]

In almost all of these instances small round valves were used for this purpose.

A good pallet and slider chest is difficult to make, and those constructed by indifferent workmen out of indifferent lumber will cause trouble through "running"—that is, leakage of wind from one pipe to another. In poor chests of this description the slides are apt to stick when the atmosphere is excessively damp, and to become too loose on days when little or no humidity is present.

Individual pallet chests are cheaper to make and they have none of the defects named above. Most of these chests, however, are subject to troubles of their own, and not one of those in which round valves are employed permits the pipes to speak to advantage.

Willis, Hope-Jones, Carlton C. Michell and other artists, after lengthy tests, independently arrived at the conclusion that the best tonal results cannot by any possibility be obtained from these cheap forms of chest. Long pallets and a large and steady body of air below each pipe are deemed essential.[2]

As previously stated, the vast majority of organs built fifty years ago used no higher wind pressure than 3 inches. Hill, in 1833, placed a Tuba stop voiced on about 11 inches in an organ he built for Birmingham Town Hall (England), but the tone was so coarse and blatant that such stops were for years employed only in the case of very large buildings.[3] Cavaillé-Coll subsequently utilized slightly increased pressures for the trebles of his flue stops as well as for his larger reeds. As a pioneer he did excellent work in this direction.

To Willis, however, must be attributed greater advance in the utilization of heavy pressures for reed work. He was the first to recognize that the advantage of heavy wind pressure for the reeds lay not merely in the increase of power, but also in the improvement of the quality of tone. Willis founded a new school of reed voicing and exerted an influence that will never die.

In organs of any pretensions it became his custom to employ pressures of 8 to 10 inches for the Great and Swell chorus reeds and the Solo Tubas in his larger organs were voiced on 20 or 25 inches.

He introduced the "closed eschallot" (the tube against which the tongue beats in a reed pipe) and created a revolution in reed voicing. He has had many imitators, but the superb examples of his skill, left in English Cathedral and town hall organs, will be difficult to surpass.

Prior to the advent of Hope-Jones (about the year 1887) no higher pressure than 25 inches had, we believe, been employed in any organ, and the vast majority of instruments were voiced on pressures not exceeding 3 inches. Heavy pressure flue voicing was practically unknown, and in reeds even Willis used very moderate pressures, save for a Tuba in the case of really large buildings.

Hope-Jones showed that by increasing the weight of metal, bellying all flue pipes in the centre, leathering their lips, clothing their flues, and reversing their languids, he could obtain from heavy pressures practically unlimited power and at the same time actually add to the sweetness of tone produced by the old, lightly blown pipes. He used narrow mouths, did away with regulation at the foot of the pipe, and utilized the "pneumatic blow" obtained from his electric action.

He also inaugurated "an entirely new departure in the science of reed voicing." [4]

He employs pressures as high as fifty inches and never uses less than six. His work in this direction has exercised a profound influence on organ building throughout the world, and leading builders in all countries are adopting his pressures or are experimenting in that direction.

Like most revolutionary improvements, the use of heavy pressures was at first vigorously opposed, but organists and acousticians are now filled with wonder that the old low-pressure idea should have held sway so long, in view of the fact that very heavy wind is employed for the production of the best tone from the human voice and from the various wind instruments of the orchestra.

Karl Gottlieb Weiglé, of Stuttgart, was a little in advance of many of his confrères in using moderately heavy pressures, but he departed from the leather lip and narrow mouth used by Hope-Jones and has obtained power without refinement.

In employing these heavy pressures of wind, increased purity and beauty of tone should alone be aimed at. Power will take care of itself.

The "organ beater" of bygone days was invariably accompanied by the "organ pumper," often by several of them. There is a well-known story of how the man refused to blow any longer unless the organist said that "wehad done very well to-day." The organ pumper's vocation is now almost entirely gone, especially in this country, although we know of organs in England which require four men "to blow the same" unto this day.

When Willis built the great organ in St. George's Hall, Liverpool, in 1855, he installed an eight-horsepower steam engine to provide the wind supply. There is a six-horse steam engine in use in Chester Cathedral (installed 1876).

Gas and petrol (gasoline) engines have been used extensively in England, providing a cheaper, but, with feeders, a less controllable, prime mover. By far the commonest source of power has been the water motor, as it was economical and readily governed, and as water pressure was generally available, but the decline of the old-time bellows, with the fact that many cities to-day refuse to permit motors to be operated from the water mains, have given the field practically to the electric motor, now generally used in connection with some form of rotary fans. The principle of fans in series, first introduced by Cousans, of Lincoln, England, under the name of the Kinetic Blower, is now accepted as standard. This consists of a number of cleverly designed fans mounted in series on one shaft, the first delivering air to the second at, say, 3-inch pressure, to be raised another step and delivered to the next in series, etc., etc. This plan permits tapping off desired amounts of air at intermediate pressures with marked economy, and as it is slow speed, and generally direct connected with its motor on the same shaft, it is both quiet and mechanically efficient.

[1] One object of this was to prevent what was called "robbing." While the pressure of the wind might be ample and steady enough with only a few stops drawn, it was found that when all the stops were drawn the large pipes "robbed" their smaller neighbors of their due supply of wind, causing them to sound flat. By giving each pipe a pallet or valve to itself, the waste of wind in the large grooves was prevented. Another object was to get rid of the long wooden slides, which in dry weather were apt to shrink and cause leakage, and in damp weather to swell and stick.

[2] A striking instance of the difference between the two kinds of pallet can be seen in All Angels' Church, New York. The organ was built originally by Roosevelt, with two manuals and his patent wind-chest. In 1890 the church was enlarged and Jardine removed the organ to a chamber some thirty feet above the floor and fitted his electric action to the Roosevelt wind-chest. At the same time he erected an entirely new Choir organ, in the clerestory, with his electric action fitted to long pallets. The superiority of attack and promptness of speech, especially of the lower notes, of the Choir over the Great and Swell organs is marvelous. The same thing can be seen at St. James' Church, New York, where the Roosevelt organ was rebuilt with additions by the Hope-Jones Organ Co. in 1908.

[3] Some congregations could not stand them and had them taken out.

[4] Wedgwood: "Dictionary of Organ Stops," p. 167.

At the commencement of the period of which we are treating, the stops belonging to the Swell organ could be drawn on that keyboard only; similarly the stops on the Great, Choir and Pedal organs could be drawn only on their respective keyboards. It is now becoming more and more common to arrange for the transference of stops from one keyboard to another.

If this plan be resorted to as an effort to make an insufficient number of stops suffice for a large building, it is bound to end in disappointment and cannot be too strongly condemned. On the other hand, if an organ-builder first provides a number stops that furnish sufficient variety of tonal quality and volume that is ample for the building in which the instrument is situated, and then arranges for the transference of a number of the stops to other manuals than their own, he will be adding to the tonal resources of the instrument in a way that is worthy of commendation. Many organs now constructed have their tonal effects more than doubled through adoption of this principle.

It is difficult to say who first conceived the idea of transference of stops, but authentic instances occurring in the sixteenth century can be pointed out. During the last fifty years many builders have done work in this direction, but without question the leadership in the movement must be attributed to Hope-Jones. While others may have suggested the same thing, he has worked the system out practically in a hundred instances, and has forced upon the attention of the organ world the artistic advantages of the plan.

His scheme of treating the organ as a single unit and rendering it possible to draw any of the stops on any of the keyboards at any (reasonable) pitch, was unfolded before the members of the Royal College of Organists in London at a lecture he delivered on May 5, 1891.

When adopting this system in part, he would speak of "unifying" this, that or the other stop, and this somewhat inapt phrase has now been adopted by other builders and threatens to become general.

Extraordinary claims of expressiveness, flexibility and artistic balance are made by those who preside at "unit (Hope-Jones) organs," but this style of instrument is revolutionary and has many opponents. Few, however, can now be found who do not advocate utilization of the principle to a greater or less degree in every organ. For instance, who has not longed at times that the Swell Bourdon could be played by the pedals? Or that the Choir Clarinet were also in the Swell?

Compton, of Nottingham, England, employs this plan of stop extension and transference, or unifying of stops, in all the organs he builds.

As additional methods facilitating in some cases the transfer of stops must be named the "double touch" and the "pizzicato touch." The former, though practically introduced by Hope-Jones and found in most of his organs built during the last fifteen years, was, we believe, invented by a Frenchman and applied to reed organs. The pizzicato touch is a Hope-Jones invention which, though publicly introduced nearly twenty years since, did not meet with the recognition it deserved until recently. The earliest example of this touch in the United States is found in the organ at Hanson Place Baptist Church, Brooklyn, N. Y., 1909.

In the French Mustel reed organ the first touch is operated by depressing the keys about a sixteenth part of an inch. This produces a soft sound. A louder and different tone is elicited upon pushing the key further down. In the pipe organ the double touch is differently arranged. The first touch is the ordinary touch. Upon exerting a much heavier pressure upon the key it will suddenly fall into the second touch (about one-eighth of an inch deep) and will then cause an augmentation of the tone by making other pipes speak. The device is generally employed in connection with the couplers and can be brought into or out of action at the will of the organist. For instance, if the performer be playing upon his Choir Organ Flute and draws the Oboe stop on the Swell organ, he can (provided the double-touch action be drawn), by pressing any key or keys more firmly, cause those particular notes to speak on the Oboe, while the keys that he is pressing in the ordinary way will sound only the Flute.

The pizzicato touch is also used mostly in connection with the couplers. When playing upon a soft combination on the Great, the organist may draw the Swell to Great "pizzicato" coupler. Whenever now he depresses a Great key the Swell key will (in effect) descend with it, but will be instantly liberated again, even though the organist continue to hold his Great key. By means of this pizzicato touch (now being fitted to all Hope-Jones organs built in this country) a great variety of charming musical effects can be produced.

THE UNIT ORGAN.

The Unit organ in its entirety consists of a single instrument divided into five tonal families, each family being placed in its own independent Swell box. The families are as follows: "Foundation"—this contains the Diapasons, Diaphones, Tibias, etc.; "woodwind"—this contains Flutes, Oboes, Clarinets, etc.; "strings"—this contains the Gambas, Viols d' Orchestre, Dulcianas, etc.; "brass"—this contains the Trumpets, Cornopeans and Tubas; "percussion"—this contains the Tympani, Gongs, Chimes, Glockenspiel, etc.

On each of the keyboards any of the stops, from the "foundation" group, the "woodwind" group, the "string" group, the "brass" group and the "percussion" group, may be drawn, and they may be drawn at 16 feet, at 8 feet, and, in some instances, at 4 feet, at 2 feet, at twelfth and at tierce pitches.

Arranged in this way an organ becomes an entirely different instrument. It is very flexible, for not only can the tones be altered by drawing the various stops at different pitches, but the various groups may be altered in power of tone independently of each other. At one moment the foundation tone may entirely dominate, by moving the swell pedals the strings may be made to come to the front while the foundation tone disappears; then again the woodwind asserts itself whilst the string tone is moderated, till the opening of the box containing the brass allows that element to dominate. The variety of the tonal combinations is practically endless.

The adoption of this principle also saves needless duplication of stops. In the organ at St. George's Hall, England, there are on the manuals 5 Open Diapasons, 4 Principals, 5 Fifteenths, 3 Clarinets, 2 Orchestral Oboes, 3 Trumpets, 3 Ophicleides, 3 Trombas, 6 Clarions, 4 Flutes, etc., etc. In the Hope-Jones Unit organ at Ocean Grove effects equal to the above are obtained from only 6 stops. The organist of Touro Synagogue, New Orleans, has expressed the opinion that his ten-stop Unit organ is equal to an ordinary instrument with sixty stops.

SYMPATHY.

A strong reason against the duplication of pipes of similar tone in an organ is that curious acoustical phenomenon, thebête noirof the organ-builder, known assympathy, or interference of sound waves. When two pipes of exactly the same pitch and scale are so placed that the pulsations of air from the one pass into the other, if blown separately the tone of each is clear; blown together there is practically no sound heard, the waves of the one streaming into the other, and a listener hears only the rushing of the air. That the conditions which produce sound are all present may be demonstrated by conveying a tube from the mouth of either of the pipes to a listener's ear, when its tone will be distinctly heard. In other words, one sound destroys the other. Helmholtz explains this phenomenon by saying that "when two equal sound waves are in opposition the one nullifies the effect of the other and the result is a straight line," that is, no wave, no sound. "If a wave crest of a particular size and form coincides with another exactly like it, the result will be a crest double the height of each one" (that is, the sound will be augmented). * * * "If a crest coincides with a trough the result will be that the one will unify the other," and the sound will be destroyed.[1] That is why in the old-style organs the builder, when he used more than one Diapason, tried to avoid this sympathy by using pipes of different scale, but even then the results were seldom satisfactory; the big pipes seemed to swallow the little ones. In the big organ in Leeds Town Hall, England, there was one pipe in the Principal which nobody could tune. The tuner turned it every possible way in its socket without avail, and at last succeeded by removing it from the socket and mounting it on a block at a considerable distance from its proper place, the wind being conveyed to it by a tube. This is only one instance of what frequently occurred.

In the Hope-Jones organ the usual plan of putting all the C pipes on one side of the organ and all the C# pipes on the other, is departed from. The pipes are alternated and in this ingenious way sympathy is largely avoided.

[1] Broadhouse: "Musical Acoustics," p. 261.

We now come to the department of the organ which will be of more interest to the listener, viz., the various organ tones. The general shape and construction of the pipes now in use, judging from the earliest drawings obtainable, have not changed for hundreds of years. The ancients were not wanting in ingenuity and we have pictures of many funny-looking pipes which were intended to imitate the growling of a bear (this stop was sometimes labeled Vox Humana!), the crowing of a cock, the call of the cuckoo, the song of the nightingale, and the twitter of the canary, the ends of these pipes being bent over and inserted in water, just as the player blows into a glass of water through a quill in a toy symphony. Then there was the Hummel, a device which caused two of the largest pipes in the organ to sound at onceand awake those who snored during the sermon! Finally there was the Fuchsschwanz. A stop-knob bearing the inscription, "Noli me tangere" (touch me not), was attached to the console. As a reward for their curiosity, persons who were induced to touch the knob thereby set free the catch of a spring, causing a huge foxtail to fly into their faces—to the great joy and mirth of the bystanders.

In order to understand what follows we must make a short excursion into the realm of acoustics. We have already remarked upon the extreme antiquity of the Flute. The tone of the Flute is produced by blowing across a hole pierced in its side; in other words,like a stream of wind striking upon a cutting edge. It is possible to produce a tone in this way by blowing across the end of any tube made of any material, of glass, or iron, or rubber, or cane, or even the barrel of an old-fashioned door key. The primitive Flutes found in the Egyptian tombs and also depicted on the ancient hieroglyphics are made of reed or cane, about 14 inches long, possessing the usual six finger-holes. The top end is not stopped with a cork, as in the ordinary Flute, but is thinned off to a feather edge, leaving a sharp circular ring at right angles to the axis of the bore. By blowing across this ring a fair but somewhat feeble Flute tone is produced.

The six holes being closed by the fingers, the ground tone of the tube is produced. On lifting the fingers in successive order from the bottom end, we get the seven notes of the major scale. Closing the holes again and blowing harder, we get the scalean octave higher. By blowing still harder we get an octave higher still. In other words, we are now producingharmonics.

It is possible to produce from a plain tube without finger-holes or valves, such as the French Horn, by tightening the lips and increasing the pressure of the player's breath, the following series of harmonics:

Series of harmonicsSeries of harmonics

The harmonics of a pianoforte string can be easily demonstrated by the following experiment: Depress the "loud" pedal and strike any note in the bass a sharp blow. On listening intently, the 3d, 5th, and 8th (the common chord) of the note struck will be heard sounding all the way up for several octaves. In this case the other strings of the piano act asresonators, enabling the harmonics to be heard.

Coming back to our Flute again and applying the knowledge we have gained to an organ pipe, we observe:

1. That thepitchof the sound depends on the length of the tube.

2. That the pitch of the soundalsodepends on the amount of wind pressure.

From this last will be seen how important it is that the pressure of the wind in an organ should be steady and uniform. Otherwise the pipes will speak a harmonic instead of the sound intended—as, indeed, frequently happens.

When a stop is labeled "8 ft.," that means that the bottom pipe, CC is 8 feet long and the pitch will be that of the key struck. A "16-ft." stop will sound an octave lower; a "4-ft." stop an octave higher. These measurements refer to pipes which are open at the top and are only correct in the case of very narrow pipes, such as the stop called Dulciana. Wider pipes do not require to be so long in order to produce 8-ft. tone.

"If a tube * * * open at both ends be blown across at one end, the fundamental tone of the tube will be sounded; but if the hand be placed at one end of the tube, so as to effectually close it, and the open end be blown across as before, a sound will be heard exactly one octave below that which was heard when both ends of the tube were open. One of these pipes was an open pipe, the other a stopped pipe; and the difference between the two is that which constitutes the two great classes into which the flue pipes of organs are divided." [1]

Thus by stopping up the end of an organ pipe we get 8-ft. tone from a pipe only 4 ft. long, 16-ft. tone from a pipe 8 ft. long, and so on, but with loss of power and volume. The harmonics produced from stopped pipes are entirely different from those of the open ones; their harmonic scale is produced by vibrations which are as 1, 2, 3, 4, etc., those of a stopped pipe by vibrations which are as 1, 3, 5, 7. All these harmonics are also called upper partials.

The Estey Organ Company claim to have discovered a new principle in acoustics in their Open Bass pipes, of which we show a drawing opposite. This invention (by William E. Haskell) enables the builders to supply open bass tone in organ chambers and swell boxes where there is not room for full-length pipes.

Fig. 16. Estey's Open Bass Pipes--Wood and MetalFig. 16. Estey's Open Bass Pipes—Wood and Metal

Referring to the illustration, it will be seen that the pipes are partly open and partly stopped, with a tuning slide in the centre. The builders write as follows:

"The inserted tube, or complementing chamber, in the pipe is such in length as to complete the full length of the pipe. It is, as will be noted, smaller in scale than the outside pipe. The effect is to produce the vibration that would be obtained with a full-length pipe, and in no way does it interfere with the quality of tone. In fact, it assists the pipe materially in its speech. This is most noticeable in a pipe such as the 32-foot Open Diapason, which when made full length is quite likely to be slow in speech. With this arrangement the pipe takes its speech very readily and is no slower in taking its full speech than an ordinary 16-foot Open Diapason.

"We have worked this out for all classes of tone—string, flute and diapason—and the law holds good in every instance."

Helmholtz was the first to demonstrate that thequalityof all musical tones depends entirely upon the presence or absence of their upper partials. In the hollow tone of the Flute they are almost entirely absent; in the clanging tone of the Trumpet many of the higher ones are present; and if we take an instrument like the Cymbals we get the whole of the upper lot altogether.

The different qualities of tone of the organ pipes are therefore determined: (1) By the material of which the pipes are made; (2) by the shape of the pipe; (3) by the amount of wind pressure; (4) by the shape and size of the mouth, the relation of the lip to the stream of wind impinging on it from a narrow slit, and the shape and thickness of the lip itself. The manipulation of the mouth and lip to produce the tone desired is called voicing and calls for considerable artistic skill. The writer recollects an instance of a clever voicer (Gustav Schlette) taking a new organ in hand, which was not quite satisfactory, and on the following Sunday he hardly knew it again.

Another kind of harmonics must now be described, called combinational or Tartini tones (from Tartini, a celebrated Italian violinist of the XVII century, who first described them). "These tones," says Helmholtz, "are heard whenever two musical tones of different pitches are sounded together loudly and continuously." There is no necessity for giving a table of all of their tones here; we select the two most useful. If two notes at an interval of a fifth are held down, a note one octave below the lower one will be heard. So organ builders take two pipes—one 16 feet long (CCC) and one 10 2/3 feet long (GG)—which make the interval of the fifth, and, by sounding them together, produce the tone of a pipe 33 feet long (CCCC). This is the stop which will be found labeled "32-ft. Resultant." Hope-Jones makes a stop which he calls Gravissima, 64-ft. Resultant, in his large organs. Many contend that this system produces better results than if pipes of the actual lengths of 32 or 64 feet were employed. Indeed, a pipe 64 feet long would be inaudible; the human ear has its limitations and refuses to recognize tone lower than 32 feet (just as we cannot lift water by a suction pump over 32 feet)—but, these great pipesproduce harmonicswhich wonderfully reinforce the tone of the organ. Therefore their use is worth while.

The other combinational tone to which we refer is that produced by the interval of a major third. It sounds two octaves below the lower note. The writer is not aware that this has ever been used as an organ stop, but it is found written in the organ compositions of Guilmant and other first-rate composers. It will be seen that a skilful organist, with a knowledge of these tones, can produce effects from small organs not available to the ordinary player.

Reverting once more to our Flute, whose tube is shortened by lifting the fingers from the holes, it is not generally known that this can be done with an organ pipe; the writer has met with instances of it in England. The two lowest pipes of the Pedal Open Diapason were each made to give two notes by affixing a pneumatic valve near the top of the pipe. When the valve was closed the pipe gave CCC. When the organist played CCC sharp, wind was admitted to the valve, which opened, and this shortened the pipe. The device worked perfectly, only that it was not possible to hold down both CCC and CCC sharp and make "thunder"! The organist of Chester Cathedral had been playing his instrument twice daily for ten years before he found this out, and then he only discovered it when the pipes were taken down to be cleaned. It is an admirable makeshift where a builder is cramped for room.

Organ pipes are divided into three families—Flues, Reeds and Diaphones. The flues are subdivided into Diapasons, Flutes, and Strings, and we now proceed to consider each of these groups separately.

The pipes usually seen in the front of an organ belong to the Great organ Open Diapason, long regarded as the foundation tone of the instrument. The Open Diapason may vary in size (or scale) from 9 inches diameter at CC to 3 inches. The average size is about 6 inches.

The Diapasons of the celebrated old organ-builders, Father Schmidt, Renatus Harris, Green, Snetzler and others, though small in power, were most musical in tone quality. Though sounding soft near the organ, the tone from these musical stops seems to suffer little loss when traveling to the end of quite a large building. About the year 1862 Schulze, in his celebrated organ at Doncaster, England, brought into prominence a new and much more brilliant and powerful Diapason. The mouths of the pipes were made very wide and they were more freely blown. Schulze's work was imitated by T. C. Lewis, of England, and by Willis. It has also exercised very great influence on the work done by almost all organ-builders in this country, in Germany, and elsewhere. Schulze's method of treatment added largely to the assertiveness and power of the tone, but gave the impression of the pipes being overblown and led to the loss of the beautiful, musical, and singing quality of tone furnished by the older Diapasons. Hard-toned Diapasons became almost the accepted standard. Willis even went so far as to slot all of his Diapason pipes, and Cavaillé-Coll sometimes adopted a similar practice. Walker, in England, and Henry Erben, in this country, continued to produce Diapasons having a larger percentage of foundation tone and they and a few other builders thus helped to keep alive the old traditions.

In the year 1887 Hope-Jones introduced his discovery that by leathering the lips of the Diapason pipes, narrowing their mouths, inverting their languids and increasing the thickness of the metal, the pipes could be voiced on 10, 20, or even 30-inch wind, without hardness of tone, forcing, or windiness being introduced. He ceased to restrict the toe of the pipe and did all his regulation at the flue.

His invention has proved of profound significance to the organ world. The old musical quality, rich in foundation tone, is returning, but with added power. Its use, in place of the hard and empty-toned Diapasons to which we had perforce become accustomed, is rapidly growing. The organs in almost all parts of the world show the Hope-Jones influence. Few builders have failed now to adopt the leathered lip.

Wedgwood, in his "Dictionary of Organ Stops," pp. 44, 45, says:

"Mr. Ernest Skinner, an eminent American organ-builder,[2] likens the discovery of the leathered lip to the invention by Barker of the pneumatic lever, predicting that it will revolutionize organ tone as surely and completely as did the latter organ mechanism, an estimate which is by no means so exaggerated as might be supposed. The leathered Diapason, indeed, is now attaining a zenith of popularity both in England and America.[3] A prominent German builder also, who, on the author's recommendation, made trial of it, was so struck with the refined quality of tone that he forthwith signified his intention of adopting the process. A few isolated and unsuccessful experimental attempts at improving the tone of the pipes by coating their lips with paper, parchment, felt, and kindred substances, have been recorded, but undoubtedly the credit of having been the first to perceive the value and inner significance of the process must be accorded to Mr. Robert Hope-Jones. It was only at the cost of considerable thought and labour that he was able to develop his crude and embryonic scientific theory into a process which bids fair to transform modern organ building. The names of Cavaillé-Coll and George Willis, and of Hope-Jones, will be handed down to posterity as the authors of the most valuable improvements in the domains of reed-voicing and flue-voicing, respectively, which have been witnessed in the present era of organ building."

The desire for power in Diapason tone first found expression in this country by the introduction into our larger organs of what was called a Stentorphone. This was a large metal Diapason of ordinary construction, voiced on heavy wind pressure. It was most harsh, unmusical and inartistic. It produced comparatively little foundation tone and a powerful chord of harmonics, many of them dissonant. In Germany, Weiglé, of Stuttgart, introduced a similar stop, but actually exaggerated its want of refinement by making the mouth above the normal width. As knowledge of the Hope-Jones methods spreads, these coarse and unmusical stops disappear. He is without question right in urging that the chief aim in using heavy pressure should be to increase refinement, not power of tone. Sweet foundation tone produced from heavy wind pressure always possesses satisfactory power. He is also unquestionably right in his contention that when great nobility of foundation tone is required, Diapasons should not be unduly multiplied, but Tibias or large Flutes should be used behind them.

Every epoch-making innovation raises adversaries.

We learn from these that pure foundation tone does not blend. True, there are examples of organs where the true foundation tone exists but does not blend with the rest of the instrument, but it is misleading to say that "pure foundation tone does not blend." Hope-Jones has proved conclusively that by exercise of the requisite skill it does and so have others who follow in his steps. A view of the mouth of a Hope-Jones heavy pressure Diapason, with inverted languid, leather lip and clothed flue, is given in Figure 17.

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