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​​​​​​Author: Jonathan Lindhorst,

D.Mus candidate, Schulich School of Music of McGill University, member of the Centre for Interdisciplinary Research in Music Media and Technology (CIRMMT)

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Tone Clock Theory and Jazz: Applying Chromatic Tonalities to Contemporary Jazz

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Despite jazz’s unique ability to engage with and assimilate diverse influences from across the world, it has largely resisted adopting aspects of atonal or twelve-tone music, especially in an improvised context. However, in recent years, some jazz improvisers have begun to develop a post-tonal approach to improvisation using Tone-Clock Theory (TCT), a harmonic system and chromatic “map” that is free of the restrictions typically associated with serial or twelve-tone music. Codified in 1982 by Dutch composer

Peter Schat and later vastly expanded by New Zealand composer Jenny McLeod, TCT identifies twelve “chromatic tonalities” derived from the twelve possible atonal triads (Allen Forte’s trichordal set classes), which are labelled as “Hours” and organized around a circular clock face. Using a transpositional operation called ‘steering,’ these triadic sets can then be expanded to assemble a non-repeating twelve-tone harmonic field based on its interval-class, each with its own distinct ‘harmonic flavour.’ 

 

The inherent freedom of TCT has since attracted the attention of jazz improvisers, most notably American saxophonist John O’Gallagher, who has been instrumental in developing this approach and disseminating it through his book Twelve Tone Improvisations: A Method for Using Tone Rows in Jazz (Advance Music, 2013). O’Gallagher has also identified a similar trichord-based approach in the late work of John and Alice Coltrane on the recording Stellar Regions (1967), providing a direct link to jazz history. In my poster session, I will give a brief explanation of the foundational principles of TCT and, drawing from both O’Gallagher’s work and my own experience as a Tone-Clock improviser and composer, I will demonstrate some basic methods for practicing Tone-Clock techniques and applying them creatively to both improvisation and composition, showing how twelve-tone and atonal concepts can be used freely and musically in contemporary jazz. 

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