The experience is, on the contrary, immediate,--an impression, not a perception; and this immediacy points to the one ultimate fact in musical feeling we have so far discovered. The whole development of the scale, and the complex feeling of tonality, is an expression of the desire for consonance. Every change and correction in the scale has gone to make every note more consonant with its neighbors. And naturally the tonic is the tone with which all other tones have the most unity. Now this "return" phenomenon is a simpler case of the desire for the feeling of unity. The tonic is the epitome of all the most perfect feelings of consonance or unity which are possible in any particular sequence of tones, and is therefore the goal or resting-place after an excursion. The undoubted feeling of equilibrium or repose which we have in ending on the tonic is thus explained. Not that consonance itself, the feeling of unity, is explained. But at any rate consonance is the root of the "return," and of its development into complete tonality. The history of music is then the explicit development of acoustic laws implicit in every stage of musical feeling. That feeling covers an ever wider field. When Mr. Hadow says that the terms concord and discord are wholly relative to the ear of the listener,<1> and that the distinction between them is not to be explained on any mathematical basis, or by any a priori law of acoustics,--that it is not because a minor second is ugly that we dislike it, for it will be a concord some day,--he is only partly right. The minor second may be a "concord," that is, we may like it, some day; but that will be because w have extended our feeling of tonality to include the minor second. When that day comes the minor second will be so closely linked with other fully consonant combinations that we shall hear it in terms of them, just as to-day we hear the chord of the dominant seventh in terms of its resolution. But the basis will not be convention or custom, except in so far as custom is the unfolding of natural law. The course of music, like that of every other art, is away from arbitrary--though simple--convention, to a complexity which satisfies the natural demands of the organism. The "natural persuasion" of the ear is omnipotent. <1> W.H. Hadow, _Studies in Modern Music_, 1893. V