The Recent Revolution in Organ Building / Being an Account of Modern Developments

The dull tone of the old Diapasons was due to the absence of the upper harmonics or partials. With the introduction of the Lutheran chorale and congregational singing it was found that the existing organs could not make themselves heard above the voices. But it was discovered empirically that by adding their harmonics artificially the organs could be brightened up and even made to overpower large bodies of singers. Hence the introduction of the Mixture stops (also called compound stops), which were compounded of several ranks of pipes. The simplest form was the Doublette sounding the 15th and 22nd (the double and treble octave) of the note struck. Other ranks added sounded the 12th, 19th, and so on, until it was possible to obtain not only the full common chord, but also some of the higher harmonics dissonant to this chord, from a single key.

THE DECLINE OF MIXTURES.

Fifty years ago it was common to find the number of ranks of mixtures in an organ largely exceed the total number of foundation stops. Mixtures were inserted in the pedal departments of all large organs. Organists of the time do not seem to have objected and many of the leading players strongly opposed Hope-Jones when he came out as the champion of their abolition. These stops greatly excited the ire of Berlioz, who declaims against them in his celebrated work on orchestration.

The tone of these old organs, when all the Mixture work is drawn, is well nigh ludicrous to modern ears, and it is hard to suppress a smile when reading the statements and arguments advanced in favor of the retention of Mixtures by well-known organists of the last generation. These mutation stops still have their place in large instruments, but it is no longer thought that they are necessary to support the singing of a congregation and that they should be voiced loudly. The decline of Mixture work has in itself entirely altered and very greatly improved the effect of organs when considered from a musical point of view. The tone is now bright and clear. Mr. James Wedgwood says:

"The tendency to exaggerate the 'upper work' of the organ reached a climax in the instrument built by Gabler, in 1750, for the Monastic Church at Weingarten, near Ravensburg. This organ comprised no less than ninety-five ranks of Mixture, including two stops of twenty-one and twenty ranks, respectively. Toward the close of the Eighteenth Century, the Abt Vögler (1749-1814) came forward with his 'Simplification System,' one feature of which consisted in the abolition of excessive Mixture work. The worthy Abbe, who was a capable theorist and a gifted player, and possessed of an eccentric and, therefore, attractive personality, secured many followers, who preached a crusade against Mixture work. The success of the movement can well be measured by the amount of apologetic literature it called forth, and by the fact that it stirred the theorists to ponder for themselves what really was the function of the Mixture. * * * The announcement by Mr. Hope-Jones at the beginning of the last decade of the past century of his complete discardment of all Mixture and mutation work may fairly be stated to have marked a distinct epoch in the history of the controversy."

It is indeed strange to find that this man, who did much to discourage the use of mixtures, has never quite abandoned their employment and is to-day the sole champion of double sets of mixture pipes, which he puts in his organs under the name of Mixture Celestes! However, these are very soft and are of course quite different in object and scope from the old-fashioned mixture—now happily extinct.

FLUTES.

The chief developments in Flutes that have taken place during the period under consideration are the popularization of the double length, or "Harmonic," principle,[4] by Cavaillé-Coll, by William Thynne and others, and the introduction of large scale leather-lipped "Tibias" by Hope-Jones.

Harmonic Flutes, of double length open pipes,[5] are now utilized by almost all organ builders. Speaking generally, the tone is pure and possesses considerable carrying power. Thynne, in his Zauber Flöte, introduced stopped pipes blown so as to produce their first harmonic (an interval of a twelfth from the ground tone). The tone is of quiet silvery beauty, but the stop does not seem to have been largely adopted by other builders. Perhaps the most beautiful stop of this kind produced by Thynne is the one in the remarkable organ in the home of Mr. J. Martin White, Balruddery, Dundee, Scotland.

The Hope-Jones leathered Tibias have already effected a revolution in the tonal structure of large organs. They produce a much greater percentage of foundation tone than the best Diapasons and are finding their way into most modern organs of size. They appear under various names, such as Tibia Plena, Tibia Clausa, Gross Flöte, Flute Fundamentale and Philomela.

"The word Tibia has consistently been adapted to the nomenclature of organ stops on the Continent (of Europe) for some centuries. The word Tibia is now used in this country to denote a quality of tone of an intensely massive, full and clear character, first realized by Mr. Hope-Jones, though faintly foreshadowed by Bishop in his Clarabella. It is produced from pipes of a very large scale, yielding a volume of foundation tone, accompanied by the minimum of harmonic development. Even from a purely superficial point of view, the tone of the Tibia family is most attractive; but, further, its value in welding together the constituent tones of the organ and coping with modern reed-work is inestimable." [6]

"The Tibia Plena was invented by Mr. Hope-Jones, and first introduced by him into the organ at St. John's, Birkenhead, England, about 1887. It is a wood Flute of very large scale, with the mouth on the narrow side of the pipe. The block is sunk, and the lip, which is of considerable thickness, is usually coated with a thin strip of leather to impart to the tone the requisite smoothness and finish. It is voiced on any wind pressure from 4-inch upwards. The Tibia Plena is the most powerful and weighty of all the Tibia tribe of stops. It is, therefore, invaluable in large instruments. * * * The Tibia Profunda and Tibia Profundissima are 16-ft. and 33-ft. Pedal extensions of the Tibia Plena." [7]

"The Tibia Clausa is a wood Gedackt of very large scale (in other words, a stopped pipe), furnished with leather lips. It was invented by Mr. Hope-Jones. The tone is powerful and beautifully pure and liquid. The prevailing fault of the modern Swell organ is, perhaps, the inadequacy of the Flute work. * * * It was the recognition of this shortcoming which led to the invention of the Tibia Clausa." [8]

The Tibia Dura is another of Mr. Hope-Jones' inventions. It is an open wood pipe of peculiar shape, wider at the top than the bottom, and described by Wedgwood as of "bright, hard, and searching" tone.

The Tibia Minor was invented by Mr. John H. Compton, of Nottingham, England, one of the most artistic builders in that country. "The Tibia Minor bears some resemblance to Mr. Hope-Jones' Tibia Clausa, but being destined more for use on an open wind-chest, differs in some important respects. The stop is now generally made of wood, though several specimens have been made of metal. In all cases the upper lip is leathered. The tone of the Tibia Minor is extraordinarily effective. In the bass it is round and velvety * * * in the treble the tone becomes very clear and full * * * it forms a solo stop of remarkably fine effect, and in combination serves to add much clearness and fulness of tone to the treble, and, in general, exercises to the fullest extent the beneficial characteristics of the Tibia class of stop already detailed. If only by reason of the faculty so largely exercised, of thus mollifying and enriching the upper notes of other stops—which too often prove hard and strident in tone—the Tibia Minor deserves recognition as one of the most valuable of modern tonal inventions." [9]

The Tibia Mollis, invented by Mr. Hope-Jones, is a Flute of soft tone, composed of rectangular wooden pipes. The name Tibia Mollis is also employed by Mr. John H. Compton to denote a more subdued variety of his Tibia Minor.

Other Flutes found in organs are the Stopped Diapason, Clarabella, Clarinet Flute, Rohrflöte ("Reed-flute"), Wald Flöte, Flauto Traverso, Suabe Flute, Clear Flute, Doppel Flöte (with two mouths), Melodia, Orchestral Flute, etc., each of a different quality of tone and varying in intensity. The Philomela as made by Jardine is a melodia with two mouths.

STRINGS.

Under this head are grouped the stops which imitate the tones of such stringed instruments as the Viola, the Violoncello, the Double Bass, and more especially the old form of Violoncello, called the Viol di Gamba, which had six strings and was more nasal in tone.

At the commencement of the period herein spoken of string-toned stops as we know them to-day scarcely existed. This family was practically represented by the Dulciana and by the old slow-speaking German Gamba. These Gambas were more like Diapasons than strings.

Edmund Schulze made an advance and produced some Gambas and Violones which, though of robust and full-bodied type, were pleasant and musical in tone. They were at the time deemed capable of string-like effects.

To William Thynne belongs the credit of a great step in advance. The string tones heard in the Michell and Thynne organ at the Liverpool, England, exhibition in 1886 were a revelation of the possibilities in this direction, and many organs subsequently introduced contained beautiful stops from his hands—notably the orchestral-toned instrument in the residence of J. Martin White, Dundee, Scotland—an ardent advocate of string tone. Years later Thynne's partner, Carlton C. Mitchell, produced much beautiful work in this direction. Hope-Jones founded his work on the Thynne model and by introducing smaller scales, bellied pipes and sundry improvements in detail, produced the keen and refined string stops now finding their way into all organs of importance. His delicate Viols are of exceedingly small scale (some examples measuring only 1 1/8 inches in diameter at the 8-foot note). They are met with under the names of Viol d' Orchestre, Viol Celeste and Dulcet.[10] These stops have contributed more than anything else towards the organ suitable for the performance of orchestral music.

Haskell has introduced several beautiful varieties of wood and metal stops of keen tone, perhaps the best known being the labial Oboe and Saxophone, commonly found in Estey organs. His work is destined to exert considerable influence upon the art.

Other string-toned stops found nowadays in organs are the Keraulophon, Aeoline, Gemshorn, Spitzflöte, Clariana, Fugara, Salicet, Salicional, and Erzähler.[11]

REEDS.

As remarked in our opening chapter, pipes with strips of cane or reeds in the mouthpiece are of great antiquity, being found side by side with the flutes in the Egyptian tombs. These reeds, as those used at the present day, were formed of the outer siliceous layer of a tall grass, Arundo donax, or sativa, which grows in Egypt and the south of Europe. They were frequently double, but the prototype of the reed organ-pipe is to be seen in the clarinet, where the reed is single and beats against the mouthpiece. Of course, an artificial mouthpiece has to be provided for our organ-pipe, but this is called the boot. See Figure 19, which shows the construction of a reed organ-pipe. A is the boot containing a tube called the eschallot B, partly cut away and the opening closed by a brass tongue C, which vibrates under pressure of the wind. D is the wire by which the tongue is tuned; E the body of the pipe which acts as a resonator.

In the last half-century the art of reed voicing has been entirely revolutionized. Prior to the advent of Willis, organ reeds were poor, thin, buzzy things, with little or no grandeur of effect, and were most unmusical in quality. Testimony to the truth of this fact is to be found in old instruction books for organ students. It is there stated that reeds should never be used alone, but that a Stopped Diapason or other rank of flue pipes must always be drawn with them to improve the tone quality.

Willis created an entirely new school of reed voicing. He was the first to show that reeds could be made really beautiful and fit for use without help from flue stops. When he wanted power he obtained it by raising the pressure, in order that he might be able to afford still to restrain the tone and to consider only beauty of musical quality.

He was the first to show that every trace of roughness and rattle could be obviated by imparting to the reed tongue exactly the right curve.

He restrained too emphatic vibrations in the case of the larger reed tongues by affixing to them with small screws, weights made of brass. He quickly adopted the practice of using harmonic, or double-length tubes, for the treble notes, and secured a degree of power and brilliance never before dreamed possible.

Willis gave up the open eschallot in favor of the closed variety, thereby securing greater refinement of musical quality, though of course sacrificing power of tone. He designed many varieties of reed tubes, the most notable departure from existing standards being probably his Cor Anglais and Orchestral Oboe.

Under the guiding genius of Willis, the Swell organ—which had hitherto been a poor and weak department, entirely over-shadowed by the Great—became rich, powerful and alive with angry reeds, which were nevertheless truly musical in effect. Hope-Jones took up the work where Willis left it, and has not only pushed the Willis work to its logical conclusion, but has introduced a new school of his own.

He has taken the Willis chorus reeds and by doubling the wind pressures and increasing the loading and thickness of tongues, has produced results of surpassing magnificence. From the Willis Cor Anglais he has developed his Double English Horn, from the Willis Oboe his Oboe Horn, and from the Willis Orchestral Oboe the thin-toned stops of that class now being introduced by Austin, Skinner and by his own firm. His chief claim to distinction in this field, however, lies in the production of the smooth reed tone now so rapidly coming into general use; in his 85-note Tuba; in the use of diminutive eschallots with mere saw-cut openings; in providing means for making reed pipes stand in tune almost as well as flue pipes; and in the utilization of "vowel cavities" for giving character to orchestral-toned reeds.

The latter are of particular interest, as their possibilities are in process of development. The results already achieved have done much to make the most advanced organ rival the orchestra.

To exemplify the principle of the vowel cavities Hope-Jones was in the habit, in his factory in Birkenhead, England, in 1890, of placing the end of one of his slim Kinura reed pipes in his mouth and by making the shape of the latter favor the oo, ah, eh, or ee, entirely altered and modified the quality of tone emitted by the pipe.

Some years ago in an organ built for the Presbyterian Church, Irvington-on-Hudson, N. Y., Hope-Jones introduced a beating reed having no pipes or resonators of any kind. He is using this form of reed in most of his organs now building.

In England this vowel cavity principle has been applied to Orchestral Oboes, Kinuras and Vox Humanas, but in this country it was introduced but seven years ago and has so far been adapted only to Orchestral Oboes. At the time of writing it is being introduced in connection with Hope-Jones' Vox Humanas and Kinuras. Examples are to be seen in the Wanamaker (New York) organ; in Park Church, Elmira; Buffalo Cathedral; Columbia College, St. James' Church, New York; College of the City of New York; Ocean Grove Auditorium, and elsewhere. There undoubtedly lies a great future before this plan for increasing the variety of orchestral tone colors. Figure 20 shows a vowel cavity applied to a Vox Humana (Norwich Cathedral, England), Figure 21 to an Orchestral Oboe (Worcester Cathedral, England), and Figure 22 to a Kinura (Kinoul, Scotland).

Builders who have not mastered the art of so curving their reed tongues that buzz and rattle are impossible have endeavored to obtain smoothness of tone by leathering the face of the eschallot. This pernicious practice has unfortunately obtained much headway in the United States and in Germany. It cannot be too strongly condemned, for its introduction robs the reeds of their characteristic virility of tone. Reeds that are leathered cannot be depended upon; atmospheric changes affect them and put them out of tune.

The French school of reed voicing, led by Cavaillé-Coll, has produced several varieties that have become celebrated. Many French Orchestral reeds are refined and beautiful in quality and the larger Trumpets and Tubas, though assertive and blatant, are not unmusical. The French school, however, does not appear to be destined to exercise any great influence upon the art in this country. (For further information regarding reeds see chapter on tuning.)

UNDULATING STOPS—CELESTES.

The writer is not aware who first introduced into the organ a rank of soft-toned pipes purposely tuned a trifle sharp or flat to the normal pitch of the organ, so as to cause a beat or wave in the tone. Fifty years ago such stops were sparingly used and many organists condemned their employment altogether. Stops of the kind were hardly ever found in small organs and the largest instruments seldom contained more than one.

A great development in this direction has taken place and further advance seems to be immediate. Already most builders introduce a Celeste into their small organs and two or three into their larger instruments—whilst Hope-Jones' organs are planned with Vox Humana Celestes, Physharmonica Celestes, Kinura Celestes and even Mixture Celestes!

Most modern Celestes are tuned sharp, the effect being more animated than if it were tuned flat; but the aggregate effect and general utility of the stop are greatly enhanced by the use of two ranks of pipes, one being tuned sharp and the other flat to the organ pitch. A three-rank Celeste (sharp, flat, and unison) formed one of the novel features of the organ in Worcester Cathedral, England, built by Hope-Jones in 1896. Wedgwood credits its invention to Mr. Thomas Casson. The three-rank Celeste is also to be found in the organs of the Bennett Organ Company.

Apart from the inherent beauty of the tones there is much to be said in favor of the presence of these stops—if the organ is to be used as an adjunct to, or a substitute for, the orchestra. The whole orchestra is one huge and ever-varying "Celeste." Were it not so its music would sound dead and cold. Few of the instrumentalists ever succeed in playing a single bar absolutely in tune with the other components of the band.

PERCUSSION STOPS.

This class of stop is also now finding its way into organs more generally than heretofore. Resonating gongs giving, when skillfully used, effects closely resembling a harp have been introduced freely by the Aeolian Company in its house organs, and there seems no possible objection to such introduction. The tone is thoroughly musical and blends perfectly with the other registers. Under the name of "Chimes" these resonant gongs are now finding place in many Church and Concert organs. Tubular bells are also used in a similar capacity by all the leading organ-builders,

The greatest development in this direction is found in the Hope-Jones Unit Orchestra. In these instruments fully one-third of the speaking stops rely on percussion for production of their tones. Even small instruments of this type have all got the following percussion stops: Chimes, Chrysoglott, Glockenspiel, Electric Bells (with resonators), Xylophone, and carefully-tuned Sleigh Bells—in addition to single percussive instruments, such as Snare-drum, Bass-drum, Kettle-drum, Tambourine, Castanets, Triangle, Cymbals, and Chinese Gong.

As all these tone producers are enclosed in a thick Swell box, an artist is able to employ them with as much refinement of effect as is heard when they are heard in a Symphony Orchestra.

Mr. Hope-Jones informs the writer that he has just invented an electric action which strikes a blow accurately proportioned to the force employed in depressing the key, thus obtaining expression from the fingers as in the pianoforte. He will apply this to the percussion stops in organs he may build in the future.

When skilfully employed many of these percussion stops blend so perfectly with the flue and reed pipes that they become an important integral part of the instrument—not merely a collection of fancy stops for occasional use.

THE DIAPHONE.

The invention of the Diaphone by Hope-Jones in 1894 will some day be regarded as the most important step in advance hitherto achieved in the art of organ building. The existence of patents at present prevents general adoption of the invention and limits it to the instruments made by one particular builder. In addition to this the Diaphone takes so many forms and covers so large a field that time must necessarily pass before its full possibilities are realized.

Enough was, however, done by Hope-Jones in connection with the organs he built in England a dozen or eighteen years ago to leave the experimental stage and prove the invention to be of the greatest practical importance to the future of organ building. The author's opinion that before long every new large organ will be built upon the Diaphone as a foundation, is shared by all who have had opportunity to judge. By no other means known to-day can anything approaching such grand and dignified Diapason tone be produced. Were twenty large Diapasons added to the instrument in Ocean Grove, N. J., or to that in the Baptist Temple, Philadelphia, and were the Diaphone removed, the instrument would suffer most seriously. In the Pedal department no reed or flue pipe can begin to compare with a Diaphone, either in attack or in volume of tone.

In Figure 23 we give a sectional view of the first large Diaphone made, namely that constructed for the Hope-Jones organ in Worcester Cathedral, Eng., 1896.

M is a pneumatic motor or bellows to which is attached a rod bearing the compound and spring valve V, V¹, working against the spring S. On the admission of wind (under pressure) to the box A, the motor M is caused to collapse, and thereby to open the valves V, V¹. Wind then rushes into the chamber B, and entering the interior of motor M through the passage C, equalizes the pressure in the motor. The action of the springs now serves to close the valves V, V¹, and to open out the motor M, whereupon the process is repeated.

In Fig. 24 we illustrate the Diaphone in the Hope-Jones organ built for Aberdeen University, Scotland. The action is as follows:

Wind from the organ bellows enters the pipe foot F, and raises the pressure in the chamber C. The air in the chamber will press upon the back of the valve V, tending to keep it closed. It will press also upon the bellows or motor M, and as this bellows has a much larger area than that of the valve, it will instantly collapse, and, through the medium of the tail piece T, will pull the valve V off its seat and allow the compressed air in the chamber C to rush into the resonator or pipe P. Owing to the inertia of the column of air contained in the pipe P, a momentary compression will take place at the lower end of the pipe, and the pressure of the air inside the motor M will, in consequence, be raised. The motor having now increased pressure both sides, will no longer keep the valve off its seat, and the spring S will open the motor and close the valve. The compression caused by the admission of the puff of air into the lower parts of the pipe P will be followed by the usual rarefaction, and as this rarefaction will exhaust or suck the air from the inside of the motor M, the valve will again be lifted from its seat, and the cycle of operations will be repeated as long as the wind supply is kept up. A series of regular puffs of wind will thus be delivered into the lower part of the resonator or pipe, resulting in a musical note.

Figs. 25, 26, 27 represent the first Diaphone heard in a public building in this country, namely that of a model sounded in St. Patrick's Cathedral, New York City, in 1905. In this form of Diaphone the pressure of air operating the Diaphone has been varied between 10 inches and 500 inches, without perceptible variation in the pitch of the note emitted.

Referring to Fig. 25, the chamber WW is supplied with air under pressure whenever the organist presses a key or pedal calling into use this particular note. The pressure of air enters through the circular engine supply port S, thus raising the pressure in the chamber C and forcing in an upward direction the aluminum piston P through the medium of the division D (colored black), which forms a portion of the aluminum piston.

When the lower edge of the piston has risen a certain distance it will uncover the circular engine exhaust port E, and will allow the compressed air to escape into the atmosphere. At this moment the rise of the piston will have closed the engine supply port S.

The momentum acquired by the piston (see Fig. 27) will cause it to travel upward a little further, and this upward travel of the division D will cause a compression of air to take place at the foot of the resonator or pipe R. This compression will be vastly increased through the simultaneous opening of the eight circular speaking ports SP.

The pressure of the compressed air at the foot of the resonator E will now by acting on the upper surface of the division D depress the aluminum piston until the engine supply port S is again opened.

By this time the compression at the foot of resonator R will have traveled up the pipe in the form of a sound wave, and will have been followed by the complementary rarefaction. This rarefaction on the upper side will render more effective the pressure of the compressed air again admitted through the engine supply port S on the underside of division D.

It will be seen that this cycle of operations will be repeated as long as the organist holds down his pedal or key admitting compressed air to the chamber W.

As the aluminum piston P is very light and is in no way impeded in its movement or swing, the speed of its vibration, and consequently the pitch of the note emitted, will be governed by the length of the resonator or pipe R.

The tone given by this particular form of Diaphone possesses a peculiar sweetness in quality, while the power is limited only by the pressure of air used to operate it.

In Fig. 28 we give an illustration of the form of Diaphone used in the Hope-Jones Unit organ at the Auditorium, Ocean Grove, N. J.

P is a pallet controlling the admission of air into the body of the pipe P¹. M is a motor adapted for plucking open the pallet P through the medium of strap s. The box B is permanently supplied with air under pressure from the bellows. When the valves V and V¹ are in the position shown in the drawing, the Diaphone is out of action, for the wind from the box B will find its way through the valve V (which is open) into the interior of the motor M.

When it is desired to make the note speak, the small exterior motors M¹ and M² are simultaneously inflated by the electro-pneumatic action operated by depressing the pedal key. The valve V will thereupon be closed and the valve V¹ be opened. As the pressure of air inside the motor M will now escape into the pipe or resonator P¹, the motor will collapse and the pallet P will be opened in spite of the action of the spring S which tends to keep it closed.

The wind in the box B will now suddenly rush into the lower end of the pipe P¹, and by causing a compression of the air at that point will again raise the pressure of the air inside the motor M. The pallet will thereupon close and the cycle of operations will be repeated—thus admitting a series of puffs of wind into the foot of the pipe P¹ and thereby producing a musical tone of great power.

As the valve V¹ is open, the sound waves formed in the pipe P¹ will govern the speed of vibration of the motor M. It will thus be obvious that the Diaphone will always be in perfect tune with the resonator or pipe P¹, and that the pitch of the note may be altered by varying the length of the pipe.

In Fig. 29 will be found an illustration of the Diaphone (or valvular reed) used in the Hope-Jones organ at St. Paul's Cathedral, Buffalo, N. Y.

Upon depressing a key, wind is admitted into the box B. Pressing upon the valve V it causes it to close against its seat in spite of the action of the spring S. This, however, does not take place until a pulse of air has passed into the foot of the pipe P, thereby originating a sound wave which in due time liberates the valve V and allows the spring S to move it off its seat and allow another puff of air to enter the pipe P. By this means the valve V is kept in rapid vibration and a powerful tone is produced from the pipe P. At Middlesborough, Yorkshire, England, Hope-Jones fitted a somewhat similar Diaphone of 16 feet pitch about 1899, but in this case the resonator or pipe was cylindrical in form and measured only 8 feet in length.

In Fig. 30 will be found another type of Diaphone in which the tone is produced through the medium of a number of metal balls, covering a series of holes or openings into the bottom of a resonator or pipe, and admitting intermittent puffs of air.

The action is as follows. Air under pressure enters the chamber B through the pipe foot A, and passing up the ports C, C¹, C², etc., forces the metal balls D, D¹, D², etc., upwards into the chamber E; the bottom end of the resonator or pipe. The pressure of air above the balls in the resonator E, then rises until it equals or nearly equals the pressure of air in chamber B. This is owing to the fact that the column of air in the pipe or resonator E possesses weight and inertia, and being elastic, is momentarily compressed at its lower end. This increased pressure above the balls allows them to return to their original position, under the influence of gravity. By the time they have returned to their original position, the pulse of air compression has traveled up the pipe in the form of a sound wave, and the complementary rarefaction follows.

The cycle of movement will then be repeated numerous times per second, with the result that a very pure foundation tone musical note will be produced.

The Diaphone is tuned like ordinary flue pipes and will keep in tune with them; the pressure of wind (and consequently the power of the tone) may be varied without affecting the pitch. The form of the pipe or resonator affects the quality of the tone; it may be flue-like or reedy in character, or even imitate a Pedal Violone, a Hard and Smooth Tuba, an Oboe, or a Clarinet.

In closing this chapter, the writer desires to express indebtedness for much of the material therein to the comprehensive "Dictionary of Organ Stops," by James Ingall Wedgwood, Fellow of the Society of Antiquaries, Scotland, and Fellow of the Royal Historical Society (published by the Vincent Music Co., London, England). Although the title is somewhat forbidding, it is a most interesting book and reveals an amount of original research and personal acquaintance with organs in England and the Continent that is simply marvelous. It ought to be in the library of every organist.

[1] Broadhouse, J., "Musical Acoustics," p. 27.

[2] Mr. Skinner has built some of the finest organs in this country.

[3] Much of Roosevelt's finest work is now being improved by various builders by leathering the lips.

[4] The "Harmonic" principle is described in Dom Bedos' book, published in 1780, as applied to reeds, and Dr. Bédart states that this principle was applied to flutes as early as 1804.

[5] That is to say, the pipes are made double the length actually required, but are made to sound an octave higher by means of a hole pierced half-way up the pipe.

[6] Wedgwood; "Dictionary of Organ Stops," p. 150.

[7] Wedgwood: Ibid., p. 153.

[8] Wedgwood: Ibid., p. 151.

[9] Wedgwood: Ibid. p. 153.

[10] "The Hope-Jones pattern of Muted Viol is one of the most beautiful tones conceivable."—Wedgwood: "Dictionary of Organ Stops," p. 173.

[11] The Erzähler, a modified Gemshorn, is found only in organs built by Ernest M. Skinner.

CHAPTER XI.

TUNING.

Having described the improvements in pipes, we now consider how they are tuned, and the first thing we must notice is the introduction of equal temperament.

About fifty years ago most organs were so tuned that the player had to limit himself to certain key signatures if his music was to sound at all pleasant. Using excessive modulation or wandering into forbidden keys resulted in his striking some discordant interval, known as the "wolf." The writer remembers being present at a rehearsal of Handel's "Messiah" in St. George's Hall, Liverpool, Eng., in 1866, when the organ was tuned on the unequal temperament system, and there was a spirited discussion between the conductor and Mr. W. T. Best, who wanted the orchestra to play "Every Valley" in the key of E flat so as to be in better tune with the organ.

The modern keyboard is imperfect. One black key is made to serve, for instance, for D sharp and for E flat, whereas the two notes are in reality not identical.[1] To secure correct tuning and tone intervals throughout, forty-eight keys per octave are required, instead of the twelve now made to suffice.

In what is called the equal temperament system the attempt is made to divide the octave into twelve equal parts or semi-tones, thus rendering all keys alike. To do this it is necessary to slightly flatten all the fifths and sharpen the major thirds. The difference from just intonation is about one-fiftieth of a semi-tone. Although recommended and used by J. S. Bach, equal temperament was not introduced into English organs until 1852.

Much has been lost by adopting equal temperament, but more has been gained. To a sensitive ear, the sharp thirds and fourths, the flat fifths and other discordant intervals of our modern keyed instrument, are a constant source of pain; but the average organist has become so accustomed to the defect that he actually fails to notice it!

The change to equal temperament has on the other hand greatly increased the scope of the organ and has rendered possible the performance of all compositions and transcriptions regardless of key or modulation.

The tuning of an organ is seriously affected by the temperature of the surrounding air. Increased heat causes the air in the open pipes to expand and sound sharp contrasted with the stopped pipes through which the air cannot so freely circulate. The reeds are affected differently, the expansion of their tongues by heat causing them to flatten sufficiently to counteract the sharpening named above. Hence the importance of an equable temperature and the free circulation of air through swell-boxes, as described on page 59, ante.

NEW METHOD OF REED TUNING.

Organ reed pipes, especially those of more delicate tone, fail to stand well in tune, especially when the tuner is in a hurry or when he does not know enough of his business to take the spring out of the reed wire after the note has been brought into tune.

Few persons fully understand the reason why reeds fail to stand in tune as they ought to.

Figures 31, 32, and 33 will serve to make clear the chief cause for reeds going out of tune. Figure 31 may be taken to represent a reed block, eschallot, tongue and tuning wire at rest.

In this case the tuning wire will be pressing firmly against the tongue at the point B, but said tuning wire will not be subjected to any abnormal strain.

Turning to Figure 32, if we use the reed knife and slightly lift the tuning wire at the point C, friction against the tongue at the point B will prevent said point B from moving upward. (In this connection it must be borne in mind that the co-efficient of friction in repose is much greater than the co-efficient of friction in motion.)

In consequence of the drawing up of the tuning wire at point C, and the frictional resistance at point B holding the latter steady, the lower part of the tuning wire will assume the shape shown in Figure 32, and point A will in consequence move farther away from the tongue.

Now, if the reeds be left in this state and the organ be used for any length of time, it will be found that point B of the tuning wire will have risen upward until the abnormal strain upon the tuning-wire spring has been satisfied. In consequence of this, this particular note will be sounding flatter in pitch than it ought to do.

Conversely, if the portion of the tuning wire lettered C be slightly driven down, as in Figure 33, the retarding effect of the friction of repose at point B will cause the lower portion of the tuning wire to approach nearer the tongue than it should do.

If now this reed be left in this state, after the pipe has been used for some time and the tongue has been vibrating, it will be found that point B on this tuning wire will have traveled nearer to the tip of the tongue, in order to relieve the abnormal strain upon the lower portion of the tuning wire. Point A will then have resumed its normal position.

In Figures 32 and 33, the defective action of the lower portion of the tuning spring has been purposely exaggerated in order to make the point clear. This bending of the tuning wires, however, takes place to a much larger extent than most organ builders imagine. It is the chief reason why reeds fail to stand in tune.

When point A on the reed tuning wires is rigidly supported and held by force in its normal position, reeds can be made to stand in tune almost as well as flue pipes.

Figure 34 represents the Hope-Jones method of supporting the tuning wire at point A. It consists of having a brass tube T inserted in the block moulds before the block is cast. This tube T therefore becoming an integral part of the block itself. The inside bore of tube T is of such diameter that the tuning wire fits snugly therein.

In Figure 35 another method used by him for accomplishing the same purpose is shown. In this case a lug L is cast upon the block, forming, indeed, a portion of said block. The lower end of lug L is formed into a V, which partly embraces a tuning wire and supports it in such manner as to prevent improper movement of said tuning wire at point A.

When this method of construction is employed, the reeds are very much easier to tune, and, when once tuned, will stand infinitely better than reeds made in the ordinary way.