Music Evolution: Science wants YOUR ears!

Chasing the links for that Levitin interview yesterday, I found this call for volunteers in a musical experiment:

MacCullum’s computer program creates a randomly generated pair of “Adam and Eve” “songs”–brief loops of sound. They mutate, recombine and reproduce to form a base population of 100 descendants.

Participants act as the force of natural selection by listening to the songs and rating them, from “I love it!” through “It’s OK…” to “I can’t stand it”. For every 20 songs, the 10 worst rated die off, while the 10 best rated go on to reproduce at random, with each “mating” producing two new songs. Each daughter song inherits a mixture of the parents’ computer codes, just as a biological organism inherits a mixture of its parents’ genetic codes.

“The ‘chromosomes’ in DarwinTunes are actually tree structures of code,” the researchers explain. “There is only one tree structure per song, that is, they are ‘haploid’. During recombination a small number of tree nodes are chosen at random in one parent (each node has a 1 in 1000 chance of being chosen). The same number of nodes are then chosen at random in the other parent.”

Then random mutation comes into play. Each node of a daughter’s code has a one in 1500 chance of mutating. “Eighty per cent of the mutations are ‘point mutations’ which alter the value of a single atomic piece of information (e.g. note length, note position, wavelength multiple). The remainder are ‘macro mutations’ which swap, copy, insert, delete or replace part of the tree structure.”

When 20 new songs are born, the 10 parents die off, and the process continues in the new generation.

Interested in lending your ears? Go to!