Music by natural selection
21 Jun 2012 by Evoluted New Media
Music evolves and ‘mates’ via natural selection according to new research from Imperial College London.
Researchers wanted to test the theory that cultural changes in language, art and music evolve through natural selection so programmed a computer to produce random loops of sounds and analyse the opinions of musical consumers.
“Everyone ‘knows’ that music is made by traditions of musical geniuses. Bach handed the torch to Beethoven who gave it to Brahms; Lennon and McCartney gave it to the Gallaghers who gave it to Chris Martin. But is that really what drives musical evolution?” said Armand Leroi, Professor of Evolutionay Developmental Biology.
To test if natural selection could be applied to music – and to see if they could make a pop tune – researchers developed DarwinTunes, a computer algorithm that maintains a population of 100 loops of music each eight seconds long.
“A population of short musical loops evolves as web-based listeners rate them on a scale of 1 to 5,” said Dr Bob MacCallum. “The higher rated loops get to have sex and make baby loops which form the next generation, which are rated, have sex, make babies and so on. This sexual reproduction combined with a low level of mutation provides the variation for Darwinian evolution.”
After 150 generations – around 3,000 loops – a steady rhythm became apparent and by 500 generations the sounds became more pleasant with some major chord harmony. By 1,000 generations simple melodies and complex sound textures appeared; by 2,000 generations, not much had changed in terms of musicality but new sounds and melodic elements were present. By 3,000 generations complex intertwining melodies with rhythmic accompaniments could be heard.
Researchers then tested the likeability of loops from different generations – the volunteers consistently ranked the more evolved music as more appealing; independently validating the assertion that music was improving over time.
“We knew our evolutionary music engine could make pretty good music in the hands of one user, but what we really wanted to know was if it could do so in a more Darwinian setting with hundreds of listeners providing their feedback. Thanks to our students’ and the general public’s valuable input, we can confidently say it does,” said MacCallum.
