No. of Elements. Proportional Duration. Two, 1.000 Three, 1.109 Four, 1.817 Five, 1.761 Six, 2.196 Seven, 2.583 Eight, 2.590
This progressive extension of the rhythm period is to be explained by the mechanical conditions imposed on the expression of rhythm by processes of muscular contraction and release. Were it possible freely to increase the rate of such successive innervations, we should expect to find a much greater constancy in the whole period occupied by the series of reactions which composes the unit. The comparatively unsatisfactory quality of these larger series, and the resolution of them into subgroups described elsewhere in this paper, are due to this inability to accommodate the series of motor reactions to the subjective rhythm period.
On the other hand, the temporal value of the unit which appears as the result of subjective rhythmization undergoes a progressive decrease in absolute magnitude as the rate of succession among the undifferentiated stimuli is accelerated. The series of values for units containing from two to eleven constituents is given in the following table:
No. of Elements. Duration in Seconds. Two, 2.00 Three, 1.75 Four, 1.66 Seven, 1.75 Nine, 1.50 Eleven, 0.97
If the time-value of the simple rhythm group here depended solely on the relation of the successive stimuli to the subjective rhythm period, no progressive diminution should be presented, for in proportion as the absolute value of the separating intervals decreases the true nature of this period should be more clearly manifested. It is scarcely to be doubted that the complexity of its content is likewise a determinant of the temporal value of this period, and that to this factor is to be attributed the changes which are here presented.
 Bolton reports a similar decrease
in the temporal value of
the unit, and gives the following quantitative relations:
Average length of 2-group, 1.590 secs. " " " 3-group, 1.380 " " " " 4-group, 1.228 " " " " 6-group, 1.014 " " " " 8-group, 1.160 "
In subjective rhythmization the number of elements which compose the unit is dependent solely on the relation of the subjective rhythm period to the rate of succession among such elements. In objective rhythm, as has been pointed out, a free treatment of the material is rendered impossible by the determination of specific points of increased stress, in virtue of which a new unit of change appears, namely, the whole period elapsing from any one occurrence of accentuation to its return.