VOICING AND TUNING.

The time has now come when we may bring our little organ into musical order, and reap some of the fruits of our toil.

If the processes described in previous chapters have been steadily carried out, the instrument is now complete (so far as the manual only is concerned) with the exception of the draw-stop action, which we intentionally reserve, and the external case.

We shall insert here, therefore, a few pages on voicing, the important and delicate operation by which the correct speech and distinctive tone of organ-pipes is imparted to them.

Let us warn the reader at once, and with emphasis, that the process of voicing metal pipes is so complex that a complete mastery of its practical details is by no means uniformly attained, even after years of steady practice under skilled guidance. A very sensitive and educated ear, a delicate sense of touch in the handling of fine tools, and a thorough familiarity with the tonal quality, or timbre, of the best examples of the many varieties of pipes—these gifts are essential to the successful voicer. Hence we cannot counsel beginners to attempt the voicing of metal pipes, unless they are fortunate enough to find themselves in a position to obtain lessons from some clever operator willing to give them, or unless they can gain permission to attend at some first-class factory, for the express purpose of watching the pipe-makers and voicers at work.

We shall not be deterred, however, by these considerations from describing, to the best of our ability, the business of voicing and regulating an ordinary metal pipe, pointing out specially, as we go on, all that may be necessary for the removal of defects and faults in pipes already voiced by other hands. But we must acknowledge our own obligations to the little treatise on voicing and tuning mentioned in the preface to this work. Those who obtain and peruse this thoroughly practical little tract will find all the information which they can require.

Figs. 40, 41 show the well-known forms of metal organ-pipes as seen in the Open Diapason, Principal, &c. Figs. 42, 43 give details. The languid, Fig. 42, is a little enlarged. It will be seen that the essential features of wooden pipes have their counterpart in those of metal—the language, or languid, answering to the wooden block, the conical termination to the wooden pipe-foot, the cylindrical body to the rectangular wooden tube.

We have never made any metal pipes ourselves, and we doubt if our readers will do well to embark upon an undertaking requiring special "plant" and appliances in a separate workshop, and calling for great dexterity and neatness in a class of operations familiar only to trained artisans. For the information, however, of those who choose to make the experiment, we may explain that the metal sheets from which the pipes are made are thus produced:— "The ingredients (viz. tin and lead in various proportions) are melted together in a copper and then cast into sheets, a process effected by pouring it in a molten state into a wooden trough, and running the trough rapidly along a bench faced with tick. The metal escapes from the trough through a narrow horizontal opening at the back, leaving a layer of metal behind it as it proceeds; and the wider the cutting is, of course the thicker will be the sheet of metal produced. After being cast to an approximate thickness, the metal is planed down to the precise thickness required. It is then cut into portions of the shape necessary to give to the pipes the required size and form, and is thus finally worked up."[2]

The three parts which compose the pipe are first separately prepared. The sheet of metal is rolled round a wooden cylinder or cone, called a mandrel, and the edges are soldered together. The extreme neatness of this soldered joint is secured by smearing the metal with composition, which is scraped off at that part only which is to retain the solder; but a steady hand, and long familiarity with the manipulation of the heated copper tool and with the properties of soft solder, are absolutely essential to success.

At the lower part of the body thus soldered, the mouth is formed by flattening a portion of the cylinder and by cutting away a horizontal slip of the metal. The width of the mouth is to be in all cases a quarter of the circumference of the pipe. In the case of large pipes the mouth is formed by cutting away a piece of metal of considerable size, and replacing it by a sheet called the "leaf," having the mouth cut on its lower edge.

The foot is formed in a similar manner, and has a flattened portion corresponding to that of the body.

The language, or languid, is a circular disc of much thicker stuff, bevelled off round its periphery, which is altered into a straight line at that portion which will lie beneath the mouth when the pipe is complete.

The three component parts are thus worked together.

The languid is placed on the wide opening of the foot, and the windway formed by leaving a narrow slit between the straight edge of the languid and the flattened lip of the foot. The two are then neatly soldered together. The body is then soldered to the foot, care being taken to adjust the mouth exactly opposite to the windway.

The larger pipes have ears, namely, rectangular pieces of metal soldered on each side of the mouth.

Thus completed and cleaned over, the pipes are handed to the voicer.

It will be remembered that we left a wooden pipe, similarly put together but unvoiced, in an earlier portion of this book. We have now to explain that both classes of pipes pass through a similar or analogous course of treatment at the hands of the voicer.

With small metal tools, called notchers, of which he has four or five, he cuts a row of nicks in the straight edge of the languid, causing it to resemble somewhat the edge of a saw. These nicks or notches, coarse or fine, close together or at rarer intervals, as the case may be, conduct the sheet of wind from the foot-hole against the upper lip of the mouth, and influence to a most important extent the character of the tone.

In a similar way, and using a file ground to a saw-like edge, the operator on a wooden pipe cuts nicks in the slightly bevelled upper edge of the block, and continues or prolongs these notches obliquely across the front of the block, letting them die away or come to nothing at their extremity. Fig. 44 shows the front of a block thus treated.

The art of the voicer, however, is by no means expended upon this notching of the languids and blocks. It extends to the accurate and nice adjustment of the height of the mouth, the aperture of the foot-hole, and the width of the windway. All these will bear strict proportion to the scale or size of the body of the pipe, and to the weight or pressure of the wind.

It will be seen, therefore, that the tone, quality, or timbre of an organ-pipe, and therefore of a "stop" or set of organ-pipes, depends upon skilled attention to at least six distinct considerations, viz.:—

• a. Scale of pipe.
• b. Height of mouth.
• c. Diameter of foot-hole.
• d. Width of windway.
• e. Character of notching.
• f. Weight of wind.

It is the thorough mastery of the art of manipulating pipes, with all these essential points kept in view, which enables the voicer to produce the exquisite contrasts of tone heard in good organs between the tranquil Dulciana and the delicate Salcional; between the Violin Diapason and the Gamba; between the Keraulophon and the Viola, as variously constructed; between the fluty-toned stops, of wood or of metal, to which various names have been given: and the full chorus or combined power of a large instrument will be majestic, imposing, and dignified, or, on the other hand, shrill, harsh, and unpleasing (quality of materials being assumed to be similar), in proportion to the skill, taste, and judgment with which it is finally voiced and regulated.

We have said enough, perhaps, to justify our advice that metal pipes be procured in a finished condition from competent makers.

Our little organ contains two metal stops, viz. a Dulciana (or a small Open Diapason) from Tenor C to f in alt, and a Principal of 4 feet throughout. Each of these, made of good metal, should cost £6 or £7. Cheap pipes mean inferior metal, and this we cannot recommend in any organ, great or small. The nearer the approach made to pure tin the better (other essential points being assumed) will be the quality of the tone.

In ordering the pipes, the weight or pressure of wind on which they are to speak must be carefully specified. This may be easily ascertained by using a wind-gauge, a little instrument which we sketch in its simplest form in Fig. 45. It consists of a glass tube, bent as shown in the figure (this can be done at any glass-blower's or optician's), and having its lower end inserted in a wooden pipe-foot. Planting the gauge on any hole of full size in any part of the sound-board, we pour a little water into the bent part or dip of the gauge. On blowing the bellows steadily, and depressing the key on the manual corresponding to the groove on which the gauge is placed, the water will be depressed in the inner column, and will rise in the outer. By adjusting the weights on the bellows we may make this difference in the levels of the two columns greater or less as we please. In our organ we shall have a "2-inch wind;" that is to say, we shall load the bellows so that the gauge may indicate a difference of 2 inches between the two columns.

We may note here that about 7 lbs. per square foot of surface of top-board will be required to give this pressure. Pieces of old cast iron about an inch thick may be procured at any foundry, and form the most suitable material for weights.

The voicer having worked to a 2-inch wind, it is probable that when the new metal pipes are planted in their places they will speak with charming evenness and truth. If some or any of them, however, betray some defects, it will be well not to meddle with them until we have satisfied ourselves that the fault does not belong to our own mechanism. If, for instance, one pipe should be softer or less prompt and clear than the others, let us be sure that the flow of wind to that pipe is not interrupted or throttled by a chip in the wind-hole or (if there is conveyancing) in the channel. This will be ascertained by planting the pipe for the moment on some other groove than its own. If the holes and channels are all clear, and the pallet is opened freely by the key, the fault must be in the pipe. This may have suffered some little injury in the packing case, e.g. the lower lip may have been nipped too close to the edge of the languid, thus reducing the width of the windway. This may be carefully rectified with the flat blade of a common table-knife, or similar object. Or the languid itself may have been bent or depressed by the weight of another pipe, packed within it to save room in the case. If this is so, the languid must be carefully pushed back to the level by a stout wire or rod inserted through the foot-hole. If the upper lip has been pressed inwards, we must counsel the utmost care in bringing it back to its position. The pipe should be sent back to the maker if the distortion is serious or considerable. If it is slight we may rectify it by passing a slip of iron bent into the shape of the letter L through the mouth, and thus pulling forward the whole of the lower par of the "leaf," preserving its regular slope as before. If the mouth, lips, and languid are all right, it is possible that by some accident the size of the foot-hole has been reduced. It may be cautiously enlarged with a penknife or with a broach; and if under other circumstances the foot-hole requires reduction, this maybe done by gently rapping or hammering the metal round the aperture with the flat side of a chisel. The builders have a heavy brass cone for effecting this reduction called a "knocking-up cup." Similar brass cones, we may here add, are used in tuning. They are expensive, however.

All that we have said of possible defects in metal pipes applies, mutatis mutandis, to wooden pipes; and as we make these ourselves we may deal more boldly with them.

An unvoiced wooden pipe will generally emit a chirp or whistle before its note. The nicking of the block will remove this, but if we overdo this nicking we shall hear a huskiness or buzzing equally or more disagreeable. This husky quality may also be due to a too wide windway; in this case, remove the cap and rub the inside face of it on a sheet of glass-paper pinned down upon a board, or plane off the inside face and file the windway anew. If the mouth has been cut too high, there may be nothing for it but to take off the front board and remake the pipe. If the pipe, in other respects good, is too loud, plug the foot-hole with neat flat plugs. If it is too soft, the pipe-foot may have been imperfectly bored, or may be defective in some way, or chips may have been left in the throat of the pipe. Ill-fitting stoppers are a fruitful source of defects in wooden stopped pipes. Refit them in every case of doubt, and leave no room for misgivings as to the soundness of the joints of the pipe near the top.

We must point out to our readers that strength, sonority, or power must on no account be expected from wooden pipes. A tone utterly harsh and intolerable will be the result of over-blowing the Stopped Diapason or Flute, stops of which the characteristic quality should only be tranquil sweetness and softness. The flute of 4-feet tone, especially, cannot be too delicate, and in its upper octave great patience will be requisite in the adjustment of the tiny mouths and windways to prevent shrillness.

These remarks apply also to our fifth stop, which we have been content hitherto to call simply "Fifteenth" 2-feet. The Fifteenth proper is a metal stop of strong shrill quality, having its value in large instruments, where it is balanced by other stops in affinity with it. Such a stop would be quite unsuitable to our little organ. If we are to have a 2-feet stop at all, it should be a "Flageolet" or "Flautina," an echo, in fact, of the 4-feet Flute. This may be successfully made by diligent operators in wood, the lower part stopped, the upper part open. The professional voicers produce the fluty quality from ordinary metal Fifteenths by peculiar treatment of the mouth. In foreign organs such stops are generally or often of conical form, the narrow aperture at the top. These stops (which may also be of 4-feet or 8-feet pitch) usually bear the names "Gems-horn" or "Spitz-flute."

We may dismiss the subject of Tuning with a very few remarks. The general principles of Temperament—that is to say, of the compromise or adaptation requisite in the modern scale of an octave containing twelve semitones—are not peculiar to organs, and may be studied in any treatise. Mr. Hopkins exhausts the subject in a very interesting chapter of his great work. Our useful little tract on voicing gives all needful information. A sensible and practical pamphlet on the same subject has been published by Mr. Hemstock, organist of Diss.

You will begin with Regulation, that is, with equalising the power or strength of the pipes composing each stop. Bestow every care on this, especially in the upper ranges of the small wooden pipes. The pleasing effect of the organ will greatly depend upon success in this operation.

When satisfied on this point, tune your wooden pipes to the metal Principal, which has been sent from the maker's ready tuned and voiced. After this rough approximation to absolute correctness, go over the whole organ with great deliberation and care, following the rules given in the works which we have cited, or in any one of them. A second or third tuning may be requisite before a sensitive ear is quite satisfied.

Cones and cups of boxwood, or made of sheet copper with brazed seams, may be used in the absence of the expensive cast-brass articles.