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.
HARMONY. The practice of combining sounds of different pitch, which is called Harmony, belongs exclusively to the music of the most civilised nations of modern times. It seems to be sufficiently proved that the ancient Greeks, though they knew the combinations which we call chords and categorised them, did not make use of them in musical performance. This reticence probably arose from the nature of their scales, which were well adapted for the development of the effective resources of melody, but were evidently inadequate for the purposes of harmony. In looking back over the history of music it becomes clear that a scale adapted for any kind of elaboration of harmony could only be arrived at by centuries of labour and thought. In the search after such a scale experiment has succeeded experiment, those which were successful serving as the basis for further experiments by fresh generations of musicians till the scale we now use was arrived at. The ecclesiastical scales, out of which our modern system was gradually developed, were the descendants of the Greek scales, and like them only adapted for melody, which in the dark ages was of a sufficiently rude description. The people's songs of various nations also indicate characteristic scales, but these were equally unfit for purposes of combination, unless it were with a drone bass, which must have been a very early discovery. In point of fact the drone bass can hardly be taken as representing any idea of harmony proper; it is very likely that it originated in the instruments of percussion or any other form of noise-making invention which served to mark the rhythms or divisions in dancing or singing; and as this would in most cases (especially in barbarous ages) be only one note, repeated at whatever pitch the melody might be, the idea of using a continuous note in place of a rhythmic one would seem naturally to follow; but this does not necessarily imply a feeling for harmony, though the principle had certain issues in the development of harmonic combinations, which will presently be noticed. It would be impossible to enter here into the question of the construction and gradual modification of the scales. It must suffice to point out that the ecclesiastical scales are tolerably well represented by the white notes of our keyed instruments, the different ones commencing upon each white note successively, that commencing on D being the one which was more commonly used than the others. In these scales there were only two which had a leading note or major seventh from the tonic. Of these the one beginning on F (the ecclesiastical Lydian) was vitiated by having an augmented fourth from the Tonic, and the one commencing on C (the ecclesiastical Ionic, or Greek Lydian) was looked upon with disfavour as the 'modus lascivus.' These circumstances affected very materially the early ideas of harmony; and it will be seen that, conversely, the gradual growth of the perception of harmonic relations modified these ecclesiastical scales by very slow degrees, by the introduction of accidentals, so that the various modes were by degrees fused into our modern major and minor scales.
The earliest attempts at harmony of which there are any examples or any description, was the Diaphony or Organum which is described by Hucbald, a Flemish monk of the tenth century, in a book called 'Enchiridion Musicæ.' These consist for the most part of successions of fourths or fifths, and octaves. Burney gives an example from the work, and translates it as follows:—
