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 t...