In this thesis dissertation, the author offers a detailed overview of music composition practice using Cellular Automata (CA) and addresses the problem of finding rules from an artists perspective in the context of music practice. He demonstrates a new perspective on the rule space structure of CA, this is achieved through empirical observation of a fundamental connection between state space and rule space. His methodology combines experimental music composition and reflective practice in its approach. Focused investigations based on this methodology are presented with the intention of forming a bridge between the art and science communities.