Metabolizing Music

The paper introduces Metamuse, a program that analyzes a piece of music by breaking it into its component parts and then reassembling it into a similar piece. This is done through autocatalytic set theory, which effectively allows portions of a string to break apart other portions, much like a conventional chemical reaction. The end result of this process is a set of substrings that reflect the overall structure in that they are biased towards repetitive patterns present within the piece as a whole. The autocatalytic process can then be run in reverse until a target goal is reached. Metamuse allows for a certain degree of evolution, since strings are allowed to copy themselves after catalyzing a reaction, with mutations sometimes occurring as a result. In this way a fitness metric is introduced such that strings which catalyze a number of reactions will be deemed more fit than others. Strings which are unable to catalyze reactions are excluded from the autocatalytic set and not allowed to replicate. In this way, self-organizing behavior can be simulated, thereby allowing for variations of a musical piece to be constructed in a non-deterministic manner.