This should not be taken as a more or less poetical account under the metaphor of motion. These "leanings" are literal in the sense that one note does imply another as its natural complement and satisfaction and we seek to reach or make it. The striving is an intrinsic element, not a by-product for our understanding. There is another point to note. The "sense of potential and coming integration" is a strong factor of melody. If it cannot be said that the first note implies the last, it is at least true that from point to point the next step is dimly foreseen, and this effect is cumulative. If melody is an ever-hindered striving for the goal, at least the hindrances themselves are stations on the way, each one as overcome adding to the final momentum with which the goal is reached. It is like an accumulation of evidence, a constellation of associations. AB foretells C; but ABCDEF rushes yet more strongly upon G. So it is that the irresistibleness, the "unalterable rightness" of a piece of music increases from beginning to end. The significance of this essential internal necessity of progression cannot be overestimated. The unalterable rightness of music is founded on natural acoustic laws, and this "rightness" is fundamental. A melody is not right because it is beautiful, it is beautiful because it is right. The natural tendencies point out different paths to the goal; and thus different ways of being beautiful; but the nature of the relation between point and point, the nature of the progression, that is, the nature of melody, is the same. Up to this point we have consistently abstracted from the element of rhythm in melody. Strictly speaking, however, it is impossible to do so. The individuality of a melody is absolutely dependent on its rhythm, that is, on the relative time-value of its tones. Gurney has devoted some amusing pages to showing the trivial, dragging, lustreless tunes that result from ever so slight a change in the rhythm of noble themes, or even in the distribution of rhythmical elements within the bar. The reason for this is evident. The nature of melody in the sense of sequence consists in the varied answers to the demands of the ear as felt at each successive point. Now it is clear that such "answer" can be emphasized, given indifferently, held in suspense, in short, subjected to all kinds of variation as well by the rhythmical form into which it is cast, as by the different choice of possibilities for the tone itself. The rhythm helps out the melody not only by adding to it an independently pleasing element, but, and this is indeed the essential, by reinforcing the intrinsic relations of the notes themselves. Thus it is in the highest degree true that in melody and rhythm we do not have content and form, but that, strictly speaking, the melody is tone-sequence in rhythm.