Not With The Band: How Music Evolution Mimics Biological Evolution
The Evolution of Popular Music: USA 1960–2010 (Matthias Mauch, Robert M. MacCallum, Mark Levy, Armand M. Leroi)
I really like it when science and art collide, or rather in this case, when science tries to help us understand art. Matthias Mauch at Queen Mary University of London (with Robert M. MacCallum, Mark Levy and Armand M. Leroi) has applied techniques used to understand biological evolution to study the evolution of American pop music… What? This seems like an interesting concept, and if I understand it correctly, we can make sense of music evolution the same way than we make sense of species evolution…Of course, creationists should abstain.
The researchers investigated the US Billboard Hot 100 between 1960 and 2010, analyzing the musical properties of more than 17,000 recordings that appeared in charts, demonstrating trends and evolution in people’s tastes. To analyze the musical properties of the songs, they measured them for a series of quantitative audio features, 12 descriptors of tonal content and 14 of timbre, and these descriptors, or ‘words’, were either chord, timber or harmonic changes. At the end, each song was represented as a distribution over 8 harmonic Topics (classes of chord changes) and 8 timbral Topics (such as ‘drums, aggressive, percussive’, ‘female voice, melodic, vocal’), represented in different proportions. These data were used to produce a classification of musical styles, only depending on objective musical qualities. The technique separated 13 styles whose respective popularities were plotted over time to study the evolution of pop music.
This way, the authors came up with a sort of scientific observation of music evolution, and, just like evolutionary biologists observe the disappearance of a species or a group of species when studying evolution, they observed the apparition and extinction of music styles… and the parallel doesn’t stop there, as music evolution, just like biological evolution, can be continuous or discontinuous with crisis and revolution.
So what did they find out at the end? That musical diversity has not declined after all… remember about these articles pretending that music has become more homogenized? They were apparently wrong as there is no decline in diversity of music according to this new study. Even better, diversity declined to a minimum around 1984 but increased again to a maximum in the early 2000’s.
They also found that music evolution is punctuated by revolutions, just like biological evolution, and they identified three important revolutions: a major one around 1991 (the Rap revolution) and two smaller ones around 1964 (the most complex one, concerning several styles related to Soul and Rock) and around 1983 (when New Wave, Disco and Hard Rock increased in popularity while Soft Rock and Country decreased)
And to close another debate, the British didn’t start the American revolution of 1964, since around this time, many styles were already changing in frequency. However, even though the British did not initiate the 60’s revolution in the US, they did exploit it and were imitated by many other artists.
The authors are aware of their limits though, as they admit not addressing the causes of the dynamics they have observed. In biology we have explanations due to ecological factors (due to competition for example), catastrophic events (due to asteroids or other cataclysmic events), and intrinsic constraints (due to genetics) but what could be the causes for music evolution? ‘By analogy, a causal account of the evolution of music must ultimately contain an account of how musicians imitate, and modify, existing music when creating new songs, that is, an account of the mode of inheritance, the production of musical novelty, and its constraints’ concluded the authors… Sure, but if Pharrell Williams can tell us a lot about the imitation part, there’s still a lot of research to be done to explain these complex mechanisms.
