Evo 8A (2019)
percussion trio
5 minutes
5 minutes
This piece was composed using a genetic algorithm. The algorithm starts with an initial population consisting of 20 individuals (string of 8 characters a-i, ex: ieafchgg) that were randomly generated. Each individual is assigned a fitness score according to how close they are to the target individual. The target I selected was aaaaaaaa. The higher the fitness score of an individual, the more likely they will be selected for reproduction (based on Darwin’s theory of “Survival of the Fittest”), allowing them to carry their genes (characters) to the next generation. The population continues to reproduce and evolve, generation by generation, until the target individual is reached. Evo 8A is short for “evolution to aaaaaaaa”.
Applying this to music, I assigned each character a duration: a = sixteenth note, b = sixteenth rest, c = eight note, d = eight rest, e = quarter note, f = quarter rest, g = dotted quarter, h = dotted quarter rest, and i = half note. The total number of generations it took to reach the target at the time I ran the program was 151, which I truncated to about 18 generations, selecting the first 6 generations, generations where the next highest fitness score appeared, and a few with high diversity. Some additional changes were made for musicality sake. Instead of being as precise as possible with the algorithm, I considered this more an experiment to create interesting rhythms and combinations of rhythms, and create a piece where everything eventually morphed into the same pattern.
Applying this to music, I assigned each character a duration: a = sixteenth note, b = sixteenth rest, c = eight note, d = eight rest, e = quarter note, f = quarter rest, g = dotted quarter, h = dotted quarter rest, and i = half note. The total number of generations it took to reach the target at the time I ran the program was 151, which I truncated to about 18 generations, selecting the first 6 generations, generations where the next highest fitness score appeared, and a few with high diversity. Some additional changes were made for musicality sake. Instead of being as precise as possible with the algorithm, I considered this more an experiment to create interesting rhythms and combinations of rhythms, and create a piece where everything eventually morphed into the same pattern.
