Modal Rhythm

Modal Rhythm


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.


Iavorskii, 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.
References in periodicals archive ?
The relationship of text; and music and the structural significance of pitch selection in monophonic music arc discussed by Richard Crocker in "Thoughts on Responsories," and by Leo Treitler, who focuses on the relationship between mode and triadic chains as well as pentachordal/tetrachordal divisions, and the consequences of these melodic structures for text setting in troubadour songs and in Abelard's Dolorum solatium Ernest Sanders discusses definitions of "rithmus" in eleventh- to thirteenth-century treatises on Latin poetry, and the significance of this concept of syllabic equality for modal rhythm.
Thus, it does not appear that she is familiar with work by either Ernest Sanders ("Conductus and Modal Rhythm," Journal of the American Musicological Society 38 [1985]: 439-69) or Margot Fassler ("Accent, Meter, and Rhythm in Medieval Treatises De rithmis," Journal of Musicology 5 [1987]: 164-90) on the relationship between poetry and modal rhythm.
Modal rhythm itself is the harmonic rhythm and its interaction with all other musical parameters.