a concept in music theory created by B. L. Iavorskii at the beginning of the 20th century. The term “modal rhythm” refers to the temporal distribution of a mode.
The concept is founded on the distinction made in music between unstable and stable tones; the gravitation of the unstable tones toward resolution in the stable ones is considered the foundation for musical movement and the formation of modes. Iavorskii saw the interval of the tritone as the source of instability. With its resolution the tritone forms the primary unity of stability and instability, “a single symmetrical system”; two such systems, at a distance of a semitone, make up a “double symmetrical system.” The joining of these systems forms the various modes.
The theory of modal rhythm offered a deeper treatment of the mode and allowed modes to be established that go beyond the limits of major-minor (augmented, diminished, chain, variable, double modes). The weak spot in Iavorskii’s theory is the fact that modes are constructed on a tritonal basis, which causes ancient modes devoid of a tritone (for example, the pentatonic) to be seen as incomplete variants of more complex modal formations. Iavorskii considered modal-tonal relations in light of form and rhythmic proportions (thus the name of the concept). While the concept as a whole has lost importance, many of its notions have found development in Soviet music theory.
REFERENCESIavorskii, B. Stroenie muzykal’noi rechi. Moscow, 1908.
Iavorskii, B. Uprazhneniia ν obrazovanii ladovogo ritma, 2nd ed. Moscow, 1928.
Protopopov, S. Elementy stroeniia muzykal’noi rechi. Moscow, 1930.
Iavorskii, B. Vospominaniia, stat’i i pis’ma, vol. 1. Moscow, 1964.