HARMONY, in Music, is a term which appears to have completely changed its signification since the first use of it. The ancient Greek writers, who seem to have contemplated only the succession of sounds which ive call MELODY, (see that article,) attached to such successions as were pleasing and agreeable to the ear, the name of a woman celebrated among them. But in more modern times, when the simultaneous as well as the progressive ef fects of sounds on the ear came to be practised and consi dered by writers on this subject, the term melody was ap plied to successions of sounds, particularly to such suc cessions as arc on the whole pleasing, and the term harmo ny was transferred to the newly contemplated and pleasing effects of certain intervals, when their limiting sounds are heard together, viz. 1, 3, III, 4, V, 6, VI ; VIII, 10, X, II, XII, 13, XIII ; XV,17, XVII, whose ratios are 4, , 4, „I, ; -A, ; Ste. called CON ":ORDS. See that article.
The further progress of musical discoveries next sheav ed, that certain others of the simple intervals, as I, 2, II, IV, 5, 7, VII; 8, 9, IX, XI, 12, 14, XIV ; 15, 16, XVI, &c• ; M I. 7!T ; 44, 41 VP 4, Ste. are called DISCORDS, (see that article,) might be occasionally introduced among, or in the place of some of the concords above mentioned, without destroying, but, on the contrary, heightening the pleasure of their ef fect on an ear accustomed to this mixed harmony of con cords and discords.
When this mixed harmony came to be practised on in struments having fixed notes, the pitch of which the per former could not alter, as the singer, violinist, Ste. can their notes, it was further discovered, that each of the concords and discords abovementioned, admitted of alteration, in small and unequal degrees, without altogether losing their respective characters or effects, when heard together in chords ; but the pleasing effect in composition of many of these chords, were sometimes even improved, by the alter ation of a major comma, (c, or -n;) and hereby another class of comma-deficient and of comma-redundant con cords were introduced, as 3', 3', III', 4', V', V', 6', V1', VIIP, Ste. and so of the discords, I', 2', II', II', IV`, IV' V', 7', VIP, VII', 8', Ste.
And in adapting music to only twelve fixed sounds, with in each octave, the simple or numeral intervals above men tioned were found altered, in some instances, more than the major comma, but in more numerous instances, by less and very different degrees of alteration or attemperament, in order to render music played thereon tolerably agreeable to the ear. And hence it becomes necessary for the mu
sical student to be aware of the distinctions, which we shall now proceed briefly to enumerate, viz.
.4rtcial HARMONY, implies a mixture of simple or un tempered concords, and of discords in the chords, or be tween the notes that are heard together, in any piece of music.
Equal HARMONY implies, according to one class of wri ters, an equality of harmoniousness between the different keys of music, but which is more properly called Equit. Temperament : See that article, and IsoToNic. But ac according to Dr Robert Smith, and others of our best wri ters on the subject, this term should be restricted to sys tems in which each of the six concords, 3, III, 4, V, 6, and VI, are so tempered, as to be equally and the most harmo nious or pleasing amongst themselves, while 1 and VIII remain perfect. See EQUAL Harmony.
Natural HARMONY, according to Dr Busby, admits only V of the harmonic triod, or common chord, in the ac 7,ompaniments of a piece of music.
Perfect HARMONY, implies the use of perfect or untem pered concords only, such as are produced by good singers, violinists, Ste. when they perform full music in concert, and which, as Mr liarey has shewn, in the Philosophical Magazine, vol. xxvii. pp. 206 and 314, contains all its tem peraments in the leaps or successive intervals of the me lodies of the different parts, and none of such in their com bined or simultaneous intervals of harmony, all of which are produced perfect; or without temperament. Mr Max well, in 1781, fully explained this system, as applicable to the violin, and made some attempts at applying the same to the organ, but without effect, (See MAxwELL's Scales.) Several years afterwards, however, the Rev. Mr Liston completed his EUHAR'fOxIC Organ, (see that article,) and, in 1812, published his Essay on pezfect Intonation, wherein this curious and important system is fully explained. See