From Mozart to the Beatles, music evolves as listeners get used to sounds they initially find strange or even shocking. As trailblazing music becomes mainstream, artists strike out in new directions. But in a new study, a computer program shows how listeners drive music to evolve in a certain way. Although the resulting strains are hardly Don Giovanni, the finding shows how users' tastes exert their own kind of natural selection, nudging tunes to evolve out of noise.
Bioinformaticist Robert MacCallum of Imperial College London was working with a program called DarwinTunes, which he and his colleagues had developed to study the musical equivalent of evolution in the natural world. The program produces 8-second sequences of randomly generated sounds, or loops, from a database of digital "genes." In a process akin to sexual reproduction, the loops swap bits of code to create offspring. "Genetic" mutations crop up as new material is inserted at random. The "daughter" loops retain some of the pitch, tone quality, and rhythm of their parents, but with their own unique material added.