HARMONY (Gr., a joining or fitting of pieces into one another), in Music, is under stood to be the union of sounds which individually appear different, but when heard together. form a collective sound called a chord (see ClioRp); or it may be explained as the inciting or flowing together of several sounds into, as it were, one sound; in conse quence of, or arising from, the consonant nature of their relative proportions to a funda mental sound. All musical compositions can be reduced to a fundamental harmony of successive chords, which, in their progression, are regulated by the rules of the of music. Dissonant as well as consonant, chords are included as forming harmony, as they are a union of several sounds that have but one fundamental sound, or bass note. in common. The harmony of chords can either be close or spread, which the position or distance of the sounds or intervals from one to another, forming the chords, deter mines. Close harmony is when the sounds composing each chord are placed so near to each other, that no sound belonging to the chord could again be interposed between any of those already present. Spread harmony is when the sounds of a chord arc placed at a greater distance from each other, so that some of them might be again inter posed between the parts of those sounds already present. Close harmony generally takes place in music in which there exists a near relationship among the different. parts, as in compositions for four male voices, in which case it becomes unavoidable, and spread harmony impossible. In choruses for mixed voices, and in instrumental com positions, spread harmony is more used, and the intervals of the chords are frequently inverted, which produces what is called double counterpoint (q.v.) In the inversion of intervals, great care must be taken to avoid a consecutive progression of such intervals as become fifths by inversion; also that an alto pare should never approach nearer a bass part than the distance of an octave. Close and spread harmony are often mixed, in order that individual parts may become more melodious and easier to sing, as well as to prevent unpleasant or abrupt skips in the melody; or to avoid an equally faulty monotonous formality of movement.
Although it has been said that every chord, whether consonant or dissonant, forms harmony, it must not be understood that any combination of sounds which one may choose to sound together is harmony. A dissonant chord treated as harmony is always judged of according to the nature of its different intervals, of which there are often sonic that are treated as dissonances, although they are fundamentally consonances, only more or less imperfect. All harmony in trittsic is derived from what arc called the aliquot tones. When a string is made to vibrate, we at first think that we only hear one sound; but on closer and more careful observation, we easily discover that the fundamental sound, particularly when it is a deep one, is accompanied by others in the most perfect harmony. The accompanying sounds are exactly those of which the
chords in music are formed, and on which the foundation of the whole system of har mony in music is built. From the matheMatical proportions and the relations of the accompanying sounds to the fundamental or principal sound from which they all arise (see liAmmoNrcs), it follows that harmony, in its first and natural state, can only he in four parts and it is then called perfect, or complete; in opposition fo harmony of two or three parts which cannot he complete, as some of the intervals of the chords, essential to characterize the key or scale, may be ;minting. A four-part harmony may be so arranged that five, or even more parts may appear, by means of doubling one or more of the intervals in the octave. From this increasing of the parts arises what is called the subordinate harmony, accompanying the principal or fundamental. In order to avoid faulty progressions in the subordinate harmony, care must be taken to strictly observe the rules which apply to the intervals in their fundamental state. The pur pose of the subordinate harmony is only that of ormlinenting the original, which the Germans calif/garb-any, commonly called figured harmony, but should be more properly called florid counterpoint. If it be admitted that the intervals and chords that are most consonant are also most harmonious, it naturally follows that the union of similar sounds must be the most perfect, therefore the order of perfection in which they rank must arise from their mathematical proportiobs in relation to the fundamental sound or unison. The common chord of a third, fifth, and octave to a bass non is the most pure and perfect harmony; after which follow the chord of the seventh, and the chord of the ninth. The inversions of any of these chords are all in various degrees less perfect than their original fundamental harmony. The position of the intervals in respect to the fundamental note is also an element in. the purity of chords; as, for example, a chord of the seventh in close harmony, is far less satisfactory and pleasing than it is in spread harmony, where the different intervals are at, or near, their natural distances front the fundamental note. Such considerations are of great importance to the musi cian who has to accompany from a figured bass; and also to organ-builders in arranging the composition of mixture-stops. Harmony in modern music, is therefore a succession of chords according to certain laws. In the early ages of the science, the laws of har mony were most arbitrary. , Nature presents us with solitary chords, but she does not establish their succession. A collection of chords is not music, any more than a collection of words is a speech. Music, like a discourse, must also have its phrases, periods, punctuation, etc., and all in harmony. The most useful works on harmony are those of Dr. Marx, professor Helm, and Dr. Fred. Schneider.