Computer-assisted music composition is an exciting field. Some of the most interesting possibilities of such composition are depicted in Figure 1, where the possibilities of musical information flows are illustrated. The traditional way of using the computer to compose music is to use software to produce music written in Common Music Notation (CMN), or so-called Western Music Notation, that can be printed and given to human performers who execute music using traditional instruments such as piano, guitar, or violin.

However, the computer can also be used to produce a music score automatically. In this case, the composer becomes a programmer and builds a computer program rather than a music score. A significant example of this may be found in the early work of American composer and teacher Lejaren Hiller (1924–1994), who wrote programs that composed most, if not all, of such scores as the Illiac Suite...