In this article, the author describes Color Music, an alternative notation system for musical expression. The system uses colors and shapes—powerful tools of expression—in conjunction with sound to form a new language for musical notation. The author briefly describes the history of color/sound relationships since the time of Aristotle and discusses the use of color in scores by Alexander Scriabin, Arnold Schoenberg, John Cage, Krzysztof Penderecki, Gyorgy Ligeti, Olivier Messiaen and other contemporary composers who recognized color as a tool of expression for musical notation. He also discusses the psychology and musical meaning of colors, along with the role of performers as interpreters of Color Music, and the use of standard musical forms as structural devices for applying color to scores. He describes his Color Music: Toccata and Fugue (1995) in detail.