Music consists of effects produced by the operation of certain sounds proceeding from the dulcet voice, or musical instruments, regulated by certain time, and a succession of harmonious notes, natural, grave, or flat, _i. e._, half a note below its proper tone; and acute or sharp, _i. e._, half a note above its proper key; and of such modulation of various tones, and of different value, and also of manifold denominations: the natural tones consisting of eight notes, with the addition of octaves, in various keys, with flats and sharps introduced to afford variety from the skill of the master, at different periods, to produce the most agreeable diversity in his composition; and sometimes according to the subject or words to which his music is adapted. Those musical notes, though proceeding from so small a number of radicals, are analogous to the incalculable, the endless forms, which orthography and rhetoric can afford to a well-informed orator, or elegant author, to embellish any subject. Thus from the definite number of twenty-four notes, varied in different degrees, by sharps, flats, semi-tones, &c., are produced all that is so magical, enthusiastic, and transporting in the empire of omnipotent music. Like as the alphabetic characters may be varied into myriads of forms suitable to every multifarious species of conversation or composition; in a word, a few musical notes in the hands of a master may be made by his skill to produce, from agreeable interchanges of time, harmony, &c., every variety of musical sentiment which can affect the human soul. A stronger proof cannot be adduced than will be found in the before-cited ode of “Alexander’s Feast,” by the truly poetic Dryden. In all which harmony and melody form conspicuous characteristics. And of harmony, according to the learned Mr. Mason. The sense in which the ancient Greeks viewed harmony is as follows:--“They by that term understood the succession of simple sounds according to their scale, with respect to acuteness or gravity.” Whilst it appears that by harmony, the moderns understand--“The succession of simple sounds, according to the laws of counterpoints.” From the same authority--“By melody, the ancients understood the succession of simple sounds, according to the laws of rhythm and metre, or in other words, according to time, measure, or cadence. Whereas, the moderns understand by the same term what the ancients meant by harmony, rhythm and metre being excluded.” “And the modern air is what the ancients understood by melody.” Hence, from the preceding definitions, it appears that what is now called harmony was unknown to the ancients; and they viewed that term as we now see simple melody, when we speak of it as a thing distinguished from simple modulated air, and that their term, melody, was applied to what we now call air or song.