Reed Instruments, among musical contrivances, a numerous and diverse class, including all those the tones of which are due to vibrations imparted to a body of air in a tube, throat, or chamber, by means of the pulsations of a thin lamina or tongue of wood or metal having one end fixed and the other lying over or within an aperture, and actuated by forcibly directing through this a current of air. Technically, such a lamina is termed a reed. It has two general forms. In the first, seen in the clarinet, the reed is larger than the opening through which the air is to pass, and in pulsating alternately closes and opens it, beating against its margins. This form, among European nations doubtless the earliest known, is distinguished as the beating reed. In the second, seen in the accordion, the dimensions of the reed are slightly less than those of the aperture, so that, in pulsating in consequence of an impulse and of its own elasticity, it moves within the current of air only, alternately allowing and interrupting its passage; this is hence termed the free reed.

It is proposed to consider in this place only those instruments involving the free reed. - A small, short, metallic tube, containing a single tongue or reed of this form, fitted to yield upon blowing into one end the note A or C, has long been known, and probably first in Germany and Holland, and is termed a pitch pipe. Père Amiot, a French missionary to China, early described the cheng, or Chinese organ, a small instrument consisting of a series of tubes, each having its free lamina or tongue, and acted on by the breath of the performer; and this appears to have been in common use in that country from an early period. The accordion was invented in Germany about 1829. The first reed organs, though imperfect, were made in the United States about 1818. Indeed, as early as 1812 Aaron Merrill Peasley obtained a patent for reed instruments; the wording of his claim was sufficiently general to include any form of instrument in which the tones are produced by free reeds caused to vibrate by a bellows and played by a keyboard. This patent is now in possession of the Mason and Hamlin organ company. Mr. J. H. Bazin of Canton, Mass., in 1821, is named as the second inventor. At first the instruments attracted but little attention, owing to their defective construction.

Wherever the free reed may have been first applied to the making of a small or hand instrument, the modifications thence arising, especially between about 1825 and 1835, were in rapid succession and numerous. Among the earliest of these were Wheatstone's aeolina and concertina, the latter in form of a bellows with two hexagonal faces, on the upper of which were four rows of finger stops or studs; by pressing down the latter, air was admitted to act on the corresponding tongues within. The attempts to improve the accordion, by enlarging it and extending its scale, naturally rendered it unwieldy, and thus led to a form of organ with free reeds only, and without pipes, the bellows being worked by the foot. Such were Mr. Green's seraphine and the French mélodium (in England and the United States, melodeon), one form of which latter, also termed the harmonium, appears to have been the invention of M. Debain of Paris, and improved by MM. Alexandre, father and son. The most improved form of this instrument is now known in France as the orgue-mélodium, or piano Liszt; in this country, as the Alexandre organ.

Other French instruments, of the earlier date above spoken of, were the poikilorgue and symphonium; of the German, some of which were small, and probably all ephemeral, were the aeolophon, phys-harmo-nica, aeolo-musicon, etc. In 1841 Mr. Evans of Cheltenham, England, produced a harmonium of two banks of keys and 2 1/2 octaves of pedals; but the instrument was not brought prominently forward till 1859. The objects of this inventor were to overcome the nasal and harsh quality of tone, and the slow speaking, then characterizing the French and English instruments; and he is said to have produced ultimately a pure tone of fine quality, with rapid utterance, and without loss of power. This is the form of harmonium described in English works. In it the several rows or series of reeds designed to give the different registers or parts in the harmony performed are, as in the Alexandre organ, placed horizontally across the instrument, at the same level, and separated from each other by partitions; the arrangement being such that the particular compartments or series to which the air shall be admitted in performing are determined by the knobs or stops that have been drawn out at the time. (See Organ.) In the English, as in the French instruments, also, the tardy response of the reeds to the action of air is corrected in most instances by a device known as the percussion, by which, the proper stop being drawn, the touching of any key instantly causes the blow of a small hammer on the reed, its vibration, thus promptly begun, being then continued by the current of air.

In all these forms, moreover, the agitation of the reeds is produced by means of more dense or compressed air forced out of a bellows across the reeds, and acting of course against the ordinary atmospheric pressure on the opposite side; and generally the reeds themselves are placed low in the instrument, often beneath the keyboard, so that the sound is liable to be somewhat smothered or interfered with. Some radical improvements were invented by Mr. J. Carhart (see Melodeon), the changes introduced by him having been worked out as early as 1836, and his instruments being manufactured in large numbers in Buffalo, N. Y., in the year 1846. In the application for his patent Mr. Peasley had stated that the reeds might be caused to vibrate by a force or an exhaust bellows, but that he preferred the latter. The instrument did not however come into extensive use until improved by Mr. Carhart. On the principle of the superior fulness and sweetness of those tones in the accordion made when the air is drawn into the bellows, as compared with those formed by forcing the air out, he so constructed the bellows of the melodeon that it should expel the air from the chamber into which the reed passages opened; this chamber and the space within the bellows freely communicating, and being maintained while playing in the condition of a partial vacuum by means of stout springs, which gradually distend the bellows as often as force has been used to compress and empty it of the entering air.

This required that the reeds also should be reversed, the passages admitting air into the exhausted chamber, and the reeds being acted on by the in-flowing streams of air. As a result of this arrangement, all the registers open directly into the one exhausted chamber; and they are conveniently placed in rows one over the other in the manner of shelves or successive segments, each horizontal row divided in the middle to form two registers. The construction of this part of the instrument finally adopted and now in use is the invention of Mr. E. P. Needham. Again, to open the registers, complicated connections and slides are not required, but simply for each a narrow horizontal door hinged on its lower edge, and directly pulled down by a wire making a single angle with the draw-knob. The chamber being during performance partially exhausted, if the edges of the several upright shelves or segments and of the horizontal doors to the registers are properly adapted and faced with soft leather, the external atmospheric pressure completes the connection of these parts, and secures air-tightness and strength of the whole; while in other instruments the condensed air within operates continually to strain and weaken the connections.

Thus, in this instrument, the parts are readily removed for repairs, being stayed by pins only, and as quickly put together again; and the reeds are thus directly accessible. The closing of any register is made to open a small valve within it, called a pneumatic stop, by which communication with the exhausted chamber is at once made both above and below the reeds, and the latter are then within the exhausted chamber; but upon opening the register, this valve closes, and thus other communication is cut off above, and the reeds have the exhausted space now only within, the atmosphere acting from without. The touching of any key is made to open (if the instrument has but one bank' of keys) the corresponding valve in every register. When all the registers are open, all the reeds so uncovered are caused by the entering air to sound; if some of the registers only are open, only the reeds in these can sound. With two banks of keys, couplers are required in order to put all the registers at pleasure under command of one. When by couplers the keys have thus been connected with valves in all the registers, the drawing of the knob grand jeu, or grand organ, opens all the registers, and affords remarkable power of tone and effect.

These arrangements are more common in the larger instruments or harmoniums. - The art of voicing reeds by variously curving and twisting them was invented about 1848, by Mr. Emmons Hamlin of Rome, N. Y., and first applied by the Mason and Hamlin organ company of Boston, New York, and Chicago. This invention has greatly contributed to the present perfection of these instruments, increasing the volume and improving the quality of the tones, and producing some of the differences required for the different registers. It is indeed asserted by the German makers that it was previously known in Europe; but it was not successfully employed there until after the Paris exposition of 1855, where the American reed organs created a lasting sensation. In any reed, the rapidity of vibration, and hence the pitch, depend on several particulars, chiefly the length and weight of the reed, and its relative thickness at the two ends. If the reed is thick at the free end and thin at the fixed, its tone is deep; if the reverse, acute. Hence, the reeds are roughly attuned by giving them certain lengths and thicknesses, and then more accurately by scraping off a little as may be required from the free or the fixed extremity.

The Alexandre organ is made of different sizes, the largest corresponding to a 16-ft. pipe organ, and by combinations giving seven octaves. Its usual stops are the English horn and flute, and again the bassoon and hautboy, forming the ordinary diapasons, and answering to the compass from an 8-ft. pipe; drone and clarinet, an octave below; clarion and fife, an octave above; two forte stops, to increase the volume of sound; a principal, which opens all the stops at once; the two stops first named also actuating the percussion; and two stops, expression à la main and expression of pedals, by which superior power of expression, or swell and diminuendo, is secured by merely varying the pressure of the fingers or of the feet. With these are also introduced the sourdine, modifying the tone of certain stops, voix céleste, voix humaine, musette, forte, tremolo, and combination swell. In 1870 nearly 30,000 of these instruments were manufactured in the United States.