George Allen Russell was an American jazz pianist, composer, arranger and theorist. He is considered one of the first jazz musicians to contribute to general music theory with a theory of harmony based on jazz rather than European music, in his book Lydian Chromatic Concept of Tonal Organization (1953).

The Lydian Chromatic Concept of Tonal Organization is a 1953 jazz music theory book written by George Russell. The book is the founding text of the Lydian Chromatic Concept (LCC), or Lydian Chromatic Theory (LCT). Russell's work postulates that all music is based on the tonal gravity of the Lydian mode.