HARMONIUM (French, also Orgue expressif). A well-known popular keyed instrument, the tones of which are produced by thin tongues of brass or steel, set in periodic motion by pressure of air, and called 'vibrators.' They are known also as 'free reeds'; reeds, because their principle is that of the shepherd's pipe; free, because they do not entirely close the openings in which they vibrate at any period of their movement, while those generally used in the organ, known as 'beating or striking reeds,' close the orifice at each pulsation. It is not however the vibration of the tongue itself that we hear as the tone: according to Helmholtz this is due to the escape of the air in puffs near its point, the rapidity of alternation of the puffs determining the pitch. The timbre of the note is conditioned in the first place by this opening, and then by the size and form of the channel above the tongue and its pallet hole, through which the air immediately passes. The Harmonium is the most modern of keyed instruments, if we include the nearly related American Organ, in which the vibrator is set in motion by reverse power, that is by drawing in the air; for if we go back to the earliest attempts to make instruments of the kind we are still within the I9th century. The usefulness and convenience of the harmonium have gone far to establish it, almost as a rival, in a commercial sense, to the pianoforte. It has been too much the practice to regard the harmonium only as a handy substitute for the organ, and this has been fostered by interested persons to the detriment of its individuality and the loss of the perception that it has reason to exist from its own merits as a musical instrument. It is true that like the organ the tones of the harmonium may be sustained at one power so long as the keys are kept down, and variety of timbre is obtained by using the stops; but when the Expression stop is used, by which the air reservoir is cut off and the pressure made to depend entirely upon the management of the bellows, the harmonium gains the power of increase and decrease of tone under the control of the player, who by the treadles can graduate the condensation of the wind almost as a violin-player manages his tone by the bow. To use this power artistically the harmonium-player must have skill; and few take to this instrument with anything like the high technical aim with which the pianoforte and violin are studied. There is however no reason that there should not be a school of composers and players competent to realise and develop the individual character of the instrument.

The history of the harmonium is intimately connected with that of the different wind harmonicas which from the musical fruit and baby trumpets of Nuremberg, to accordions and concertinas, have during the past fifty years had such extensive popularity. Unlike as the whole tribe of reed organs have been to any notion of music that pertained to ancient Greece, it is not a little surprising that a large vocabulary of Greek names should have been adopted to describe them. The first name, and one still in use, that of Orgue expressif, was due to a Frenchman, Grenié, who, according to Fétis (Fabrication des Instruments de Musique, Paris 1855), very early in this century imagined the construction of a keyboard instrument, which, by tongues of metal vibrating under variable pressures of atmosphere, should give nuances, or varying intensities of sound. His tongues were not 'beating' but 'free' reeds, having an alternative movement, the energy depending upon the density of the air-current affecting them. It was not a novel principle, for the Chinese cheng might have suggested the employment of it; but be this as it may, Fétis informs us that Grenie never assumed that he was the inventor of it. The experiments of Sebastian Erard with free reeds, of which Grétry thought so much, were already known. A few years later than these, about 1814 some say, and quite independently, Eschenbach of Koenigshoven in Bavaria invented a keyboard instrument with vibrators, which he named 'Organo-violine.' Then began the Greek era. In 1816 Schlimbach of Ohrdruff, improving upon Eschenbach, produced the Æoline. The next step was an apparatus for continuous wind, by Voit of Schweinfurt, who called his instrument Æolodicon. In 1818 Anton Häckel of Vienna constructed a diminutive æoline as an instrument to be used with a pianoforte, bringing it out as Physharmonica.[1] This bellows-harmonica Professor Payer took with him to Paris in 1823, and several imitations were made of it, one of which, the Aerophone of Christian Dietz, was described by him in the 6th volume of the Revue Musicale (Paris 1829). Returning to Germany, Reich of Fürth, near Nuremberg, produced at Munich in 1820 timbre registers imitating the clarinet and bassoon. The 16-foot or octave-deeper register Fétis attributes to Fourneaux père of Paris, 1836. The Melophone came out at the Paris Exhibition of 1834, and was probably made by Jacquet, whom the same authority quotes as the only maker of melophones in 1855. Elsewhere we read of an Æolodicon with bent tongues, and of a Terpodion with tongues of wood; of an Æolophone, an Adelphone, an Adiaphonon, an Harmonikon, and a Harmonine; of Melodiums, Æolians, and Panorgues; of the Poikilorgue of M. Cavaillé-Coll, etc. In England keyboard harmonicas with bellows were known by the name of Seraphine, which was not a harmonium, for it had no channels for the tongues. The oldest English patent for a seraphine is that of Myers and Storer, dated July 20, 1839.

It must be remembered that nearly all these instruments had but one complete set of vibrators to a keyboard. The Organino, a tentative instrument of Alexandra Debain (born 1809, died 1877), had two notes an octave apart on each key. To this remarkable mechanician was due the gathering up the work of all his predecessors and uniting four stops on one keyboard to produce the Harmonium. His first patent for this instrument, in Paris, is dated Aug. 9, 1840 (Notabilités de la Facture Instrumental, Paris 1857). Inventor or improver, Debain had the great merit of opening the path to contrasts in colour of free-reed tone, by means of various sized channels to the vibrators, submitted in different registers, to one keyboard. It was however unfortunate that in the defence of his rights he was induced to secure to himself the sole privilege of using the name Harmonium in France, thus forcing other makers to use the name Organ, and thus to add another stone to the cairn of confusion in musical instrument nomenclature. Of late the name Reed-organ has been used toexpress both the harmonium and the American organ, and is perhaps the best way out of a difficulty. The next great invention after Debain—attributed by Fétis to the Alexandres, father and son—was the Expression, already mentioned, the creation of a new and æsthetically more valuable harmonium. Another major invention was that of Martin, who gave the harmonium, to use a technical term, 'quicker speech,' i.e. made the sound more quickly follow the descent of the key. The invention is known as 'percussion,' and is an adaptation of the pianoforte escapement, by which a little hammer strikes the tongue at the same moment that it receives the impact of the wind. Another invention of Martins, termed 'prolongement,' enables the player to prolong certain notes after the fingers have quitted the keys. Martin governed this by knee pedals, but it is now usually effected by a stop, and knocked off at will by a little heel movement. The 'melody-attachment' of William Dawes, patented in London 1864, has the effect of making the melody-note, or air, when in the highest part, predominate, by a contrivance that shuts off all notes below the highest in certain registers of a combination. In the 'pedal-substitute' of Dawes and Ramsden this is reversed, and the lowest notes can be made to predominate over the other notes of a left hand chord. An important invention, and curious as bringing the pianoforte touch to a certain extent upon the harmonium keyboard, is the 'double touch,' invented by an English musician, Mr. Augustus L. Tamplin, before 1855, and now introduced systematically in the famous harmoniums of Mustel of Paris, and of Mr. Gilbert L. Bauer, an artistic London maker, and producing emphasised or strengthened tones by a greater depression of the key. Another important invention of the greatest delicacy is Mustel's 'pneumatic balance' (French Double Expression)—valves of delicate construction acting in the wind reservoir, and keeping the pressure of air in it practically equal, so that it cannot possibly be overblown.

Proceeding now to the structure of the harmonium it is sufficient to notice externally the keyboard and treadles as prominent features. The latter (a), moved by the feet of the player, feed the bellows (b); the air is by them forced up the wind-trunk (g) into the wind-chest (i), and from thence, while the expression-stop is not
drawn, into the reservoir (f), in a continuous and equal stream, excess in which is obviated by a, discharge pallet (e) acting as a safety valve. But when the expression-stop is drawn and the expression-hole (h) to the reservoir is consequently closed, the air acts directly upon the vibrators or tongues (m), from the feeders (c). The entire apparatus for the wind is covered by the bellows-board (k), containing the valves (j) that admit the wind to the different rows of vibrators or reed compartments, as the stops (t) may be drawn. Above the bellows-board is the 'pan' (l), sometimes erroneously called the soundboard, a board of graduated thickness in which are the channels (n)—separate chambers of air to each vibrator, determining, as said before, the different timbres. The proportions of the channels and size of the pallet-holes are found empirically. The air within the channels, set in vibration by the tongues, is highly compressed. Sometimes, to gain space and a different quality, the channels with their tongues are placed upright. A stop (t) being drawn and a key (q) depressed, wind is admitted by the action to the tongue or vibrator, and escapes by the pallet-hole (o)—at a comparatively even pressure if it comes from the reservoir, or at a varying pressure if, as already explained, the expression-stop is drawn and the wind comes from the feeders direct.
We give a cut of the percussion action already alluded to. Here q is the key, which on being depressed sends down a 'plunger' (a), which acts upon a little escapement action, with lever (b), hammer (c), and set-off (d); m is the reed, which by this arrangement is struck by the hammer and assisted to move at the moment the wind is admitted.

The harmonium has a keyboard of five octaves at 8-ft. pitch.

{ \override Score.TimeSignature #'stencil = ##f \clef bass c,4 \clef "treble^8" c'''' }

The bass stops range up to and include the e on the first line of the treble stave; and the treble stops range from the f upwards—29 and 32 notes respectively—a wider compass than any other wind instrument. In an ordinary harmonium the registers or rows of vibrators are four in number, divided, as just stated, into bass and treble, and again into front and back organs as they are technically called. The front organ has the foundation and fuller toned stops, the back organ the imitation and more reedy stops. Thus, adding the French names as they are frequently to be met with—

Front. No. 1. Diapason bass and Diapason treble—Cor Anglais and Flûte. 8-ft. pitch.

No. 2. Bourdon bass and Double Diapason treble—Bourdon and Clarinette. 16ft. pitch.

Back. No. 3. Clarion bass and Principal treble—Clarion and Fifre. 4-ft. pitch.

No. 4. Bassoon bass and Oboe treble—Basson and Hautbois. 8-ft. pitch.

M. Mustel retains this arrangement of the foundation stops in all harmoniums; Mr. Bauer in large harmoniums has doubled them. In the large Mustel instruments other stops of great beauty are added, the indisputable introduction of their ingenious maker—

Harpe Eolienne. Bass. 2-ft. pitch. Two ranks of vibrators, out of tune, the one a beat sharp, the other a beat flat, producing a tremulous effect.

Musette. Treble. 16-ft. pitch. Nasal quality.

Voix Celeste. Treble. 16-ft. pitch. Two ranks with soft quality.

Baryton. Treble. 32-ft. pitch. Nasal quality like the Musette, but broader.

The 'full organ' (grand jeu) is a drawstop giving instantly the full power of the harmonium without the out-of-tune ranks. The 'percussion' has to do with the diapason only, and not with all four rows, as originally applied by Martin. Two mechanical stops—the Tremolo, which sets the wind in motion before it reaches the vibrators, and the Sourdine, which shuts off a portion of the wind that would reach them, may be regarded now as discarded in all harmoniums of good manufacture. The Swell (recit) is like the Venetian swell in the organ. It is usually placed over the back organ, and is controlled by the 'Pneumatic Fortes,' set in motion by knee pedals, which opens the louvres by extra pressure of wind acting upon pneumatic levers. The front organ in foreign harmoniums is usually subdued by a thin board the under surface of which is covered with swansdown or other soft material; this is replaced in England by a covering of brown sheepskin or basil, also lined with swansdown. The tongues are not made of ordinary sheet rolled brass; but of a metal prepared expressly, and with some secrecy. The best is believed to be from hammered wire reduced by continued hammering to the thickness required. A broader tongue is found to give a bolder tone, but sacrifices quickness of speech; a narrower tongue is shriller. The tongues are bent in various ways, longitudinally and laterally, to gain sweetness, but the speech suffers. Tuning is effected by scraping near the shoulder to flatten the tongue, or near the point to sharpen it. The air pressure somewhat affects the tuning of the larger vibrators, but it is a merit in the harmonium that it alters little in comparison with the pianoforte or flue- work of an organ. Double touch is produced by causing the back organ to speak first, and is divided technically into the 'upper' and 'deep' touches. The harmonium has been combined in construction with the pianoforte by Debain and other makers. The timbres and nature of the two instruments are so dissimilar, not to say antagonistic, that no real benefit is to be gained by yoking them together.
  1. This name it still retained for a free-reed stop in the organ, with tremolo and swell box of its own, by Walcker of Ludwigsberg and others.