TONE-RHYTHM
182. The idea of Tone-Rhythm is expressed in every regular and perfect gradation of Tones; of values, of colors or of color-intensities, provided the eye is drawn through the gradation in one direction or in a series or sequence of directions. This happens when there is a greater tone-contrast at one end of the gradation than at the other. When the terminal contrasts are equal there is no reason why the eye should move through the gradation in any particular direction. According to our definition of Rhythm, the gradation should be marked in its stages or measures, and the stages or measures should be regular. That is certainly true, but in all regular and perfect gradations I feel that corresponding changes are taking place in corresponding measures, and I get the same feeling from such a gradation that I get from it when it is marked off in equal sections. Though the measures in regular and perfect gradations are not marked, they are, it seems to me, felt. They seem sufficiently marked by the regularity and perfection of the gradation, any irregularity or imperfection being appreciable as a break in the measure. I am inclined, therefore, to say of any regular and perfect gradation that it is rhythmical provided the direction of movement is unmistakable. The direction, as I have said, depends upon the relation of terminal contrasts. The eye is drawn toward the greater contrast, whatever that is and wherever it is. A few examples will make this clear.
In this case we have the gradation of the Scale of Values set on aground-tone of the middle value. Here there are two opposed gradations with equal contrasts at the opposite ends. The result is Balance, not Rhythm.
In this case we have a gradation of values beginning with White on White, no contrast at all, and reaching ultimately the contrast of Black and White. The eye is drawn through the tones of this gradation in the direction of this contrast, that is to say, from right to left. It is a clear case of Rhythm. If, instead of white, we had black, as a ground-tone, the movement of the rhythm would be in the opposite direction,—from left to right.
In this case, as in the first, we have equally great contrasts at the ends and no contrast at the middle. The result is Balance, not Rhythm.
In this case, disregarding possible differences of value and color-intensities, there will be a color-rhythm proceeding from right to left. The contrast to which the eye will be drawn is the color-contrast of Yellow and Violet.
In this case, disregarding possible differences of intensity, there will be a rhythm of color moving from right to left and a rhythm of values moving from left to right. Assuming that we are equally attracted by corresponding value and color-contrasts, these two rhythms, when produced, will neutralize one another and we shall havean illustration of Tone-Balance rather than Tone-Rhythm. If corresponding color and value-contrasts are not equally attractive we shall have an unequal tug-of-war between the two rhythms.
In this case we have two rhythms, one of values and one of colors, in a Harmony of Direction. The direction of movement will be from right to left.
In this case we have no change of color and no change of value, but a rhythm of the intensities of one color, in one value. The movement will be from right to left. The ground-tone might be Neutral High Light, the zero-intensity of Yellow. That would not change the direction of the movement.
In this case I have indicated a combined movement of values and color-intensities. The direction of the movement will be from right to left.
The tone-rhythms which I have described are based upon the repetition at regular intervals of a certain change of value, of color or of color-intensity. We have Harmony, of course, in the repetition of equal changes, though the changes are not the same changes. The change of value from Middle to Low Light is equal to the change from Low Light to Light, though these changes are not the same changes. The Harmony is, therefore, the Harmony of equivalent contrasts which are not the same contrasts.
183. We have more or less movement in every composition of tones whichis unbalanced, in which the eye is not held between equivalent attractions, either upon a vertical axis or upon a center. In all such cases, of tones unbalanced, the movement is in the direction of the greatest contrast. Unless the movement is regular and marked in its measures, as I think it is in all regular and perfect gradations, the movement is not rhythmical. We get Rhythm, however, in the repetition of the movement, whatever it is, in equal or lawfully varying measures, provided the direction of the movement remains the same or changes regularly or gradually. If the line of the movement is up-to-the-right forty-five degrees we have rhythm in the repetition of the movement at equal or lawfully varying intervals, without changes of direction; but we should have Rhythm, also, if the direction of the movement, in its repetitions, were changed, regularly or gradually; if, for example, the direction were changed first from up-right forty-five degrees to up-right forty degrees, then to up-right thirty-five degrees, then to up-right thirty degrees, this at equal or at lawfully varying intervals. In this way the movement of the composition repeated may be carried on and gradually developed in the movement of the series. A reference toFig. 161, p. 94, and toFig. 119, p. 68, will help the reader to understand these statements.
184. When any unbalanced composition of tones is singly inverted upon a vertical axis and the movement of the composition follows the axis, either up or down, and this movement, up or down, is repeated, up or down, we get forms of Tone-Rhythm which are also forms of Symmetrical Balance. In the inversions and repetitions of the tone-composition we have Tone-Harmony. As the tones in the repeated composition have certain positions, measures, and shapes, the Harmony, the Balance, and the Rhythm are of Positions, Measures, and Shapes as well as of Tones; so we get the combination of all the terms of Design in all the three modes of Design.