Musical Inheritance: Modification by Descent
Evolutionary biologists and computer scientists who analyzed 50 years of Billboard’s Hot 100 songs the way a paleontologist would study a fabulously intact fossil find believe their recent work on pop music illustrates a new approach to the scientific understanding of culture. Music, art and culture generally are similar to living organisms, Armand Leroi explains. They are diverse and have many different kinds of species and they all evolve trough a process Darwin called modification by descent.
“No song or specie arrives from nowhere,” Leroi told NPR Science Friday host Ira Flatow. “It happens because there was something before it.”
Leroi, an evolutionary biologist at Imperial College in London and colleagues investigated musical properties of 17,000 songs that topped the Billboard charts between 1960 and 2010. Their paper is published in Royal Society Open Science online. Although music has evolved continually, they write, the scientific measurements of changes in chords, tones, rhythms and other features uncovered three stylistic revolutions in music around 1964, 1984 and 1991. The authors say the findings point the way to a quantitative science of cultural change because they expect that statistical tools used to analyze musical structures will permit evolutionary analysis of many other dimensions of modern culture.
The greatest revolution in American pop music history, they found, was in 1991 when hip-hop entered mainstream consciousness and hit the charts. That style, exemplified by Busta Rhymes, Nas and Snoop Dogg, featured energetic speech, dominant percussion, and rare use of chords. They found that contrary to the popular notion, the style changes that took hold in 1964 did not come from the “British Invasion”—the Beatles and the Rolling Stones. Those groups were a bit ahead of the musical curve, the authors found, so their influence helped further an existing trend rather than starting one. The research identified changes in trends rather than the origins of musical styles. However the authors were able to say the 1984 change was the result of technology—musicians just loved the new synthesizers and drum machines.
For a while, Leroi told LA Times writer Eryn Brown, everything sounded like Duran, Duran. However, Leroi and colleagues say that’s the only period when diversity suffered. He says data show diversity actually has persisted over time. Further, the data on the musical revolutions show that like dramatic changes in other complex systems, changes in music took place in spurts rather than by slow, steady increment.
Read the Royal Society paper here. Watch the Edge.org “Song of Songs” video in which Leroi tells how he and musician Brian Eno talked about doing for songs what scientists have done for genes. Click here for more about Leroi’s work.