circle or return to the initial note are equivalent and include all scales with equal notes, such as the whole-tone scale. (Johnson, 2003, p. 158, n. 14) A bisector is a more general concept used to create collections that cannot be generated but includes all collections which can be generated. See also 833 cents scale Cyclic group Distance model Pythagorean tuning References Sources Carey, Norman and Clampitt, David (1989). "Aspects of Well-Formed Scales", Music Theory Spectrum 11: 187–206. Clough, Engebretsen, and Kochavi. "Scales, Sets, and Interval Cycles", 79. Johnson, Timothy (2003). Foundations of Diatonic Theory: A Mathematically Based Approach to Music Fundamentals. Key College Publishing. . External links Original concept of MOS as presented in a 1975 letter by Erv Wilson Diatonic set theory