In 1984 Clarence Barlow wrote Im Januar am Nil, which is structurally based on timbre, instead of classical and romantic harmonic systems. It is for chamber orchestra: two soprano saxophones (alternated with clarinet and bassclarinet, drum kit, piano, four violins, two cellos and one doublebass. The saxophones and string instruments are microtuned to allow the orchestra to produce the specific formants, thereby simulating vowel sounds. Barlow used a spiral to inform the structure of his music. If you look at the image below you will see his spiral. The computer was programed to produce melody to fill time equal to the segments produced from a series of spokes radiating from the center of spiral. The distances between these spokes increases as the path reaches farther out in the spiral.
Then in 2003, Dave Britton, Jack Ox, and Richard Rodriquez performed this work in the Virtual Color Organ™. Ox created a system of colors to use with music based on timbre, including vowel sounds as timbre for the human voice. This timbre based system was used for this work and for The Gridjam. Below, you can see all 21 pages with its extraordinary detail in not only the difference between instruments, but also how they are played. For instance, there are 8 different mutes that change the sounds produced by a trumpet. A family of instruments, such as strings, will all be near each other on the color-wheel: Here violins are in a warm-green range, violas are more of a 'true'green, cellos are blue-green, and double-basses are a deep blue. To see this system in action, please go to Quanta Timbre. Quanta and Hymn to Matter by Dary John Mizelle was the original inspiration for the Book of Timbre. On the next page you will see the entire score mapped with the changing timbres.