While George Russell was very active as a free-thinking composer, arranger, and bandleader, his biggest effect upon jazz was in the quieter role of theorist. His great contribution, apparently the first by a jazz musician to general music theory, was a book with the intimidating title The Lydian Chromatic Concept of Tonal Organization, where he concocted a concept of playing jazz based on scales rather than chord changes. Published in 1953, Russell's theories directly paved the way for the modal revolutions of Miles Davis and John Coltrane -- and Russell even took credit for the theory behind Michael Jackson's huge hit "Wanna Be Startin' Somethin'," which uses the Lydian scale (no, he didn't ask for royalties). Russell's stylistic reach in his own compositions eventually became omnivorous, embracing bop, gospel, blues, rock, funk, contemporary classical elements, electronic music, and African rhythms in his ambitious extended works -- most apparent in his large-scale 1983 suite for an enlarged big band, The African Game. Like his colleague Gil Evans, Russell never stopped growing, but his work is not nearly as well-known as that of Evans, being more difficult to grasp and, in any case, not as well documented by U.S. record labels.