Mathematicians Discover Music Really Can Be Infectious – Like a Virus
Linda Geddes 琳達·格迪斯
pop music is often described as catchy， but it seems you really can infect friends with your music taste. The pattern of music downloads after their release appears to closely resemble epidemic curves for infectious disease – and electronica appears to be the most infectious genre of all.
Dora Rosati， former graduate in maths and statistics at McMaster University in Ontario， Canada along with colleagues， wondered whether they could learn anything about how songs become popular using mathematical tools that are more usually applied to study the spread of infectious diseases.
Rosati said: “With a disease， if you come into contact with someone who is ill， then you have a certain chance of catching that disease. With songs， it looks very similar. The big difference is that for songs， it doesn't necessarily have to be physical contact – it could be that my friend used this cool new song in their Instagram story， so now I'm going to go and find it.”
Dr Thomas Rawson， a disease modeller at Imperial College London， said: “It's something that makes complete sense， when you consider that word of mouth is something that， much like disease， it will carry on via other people. The main difference is that there are more ways for music to spread.”
Rosati's team also calculated the basic reproduction number （R0） – a rating of a disease's ability to spread， assuming the population has zero immunity through infection or vaccination – for different music genres.
Although this varied substantially within genres， they found that dance and metal had the lowest median R0 scores at 2.8 and 3.7. Pop music was more transmissible， but it was vastly outstripped by genres such as rock and hip-hop， while electronica – a form of electronic music intended for listening， rather than dancing – had the highest R0， at 3，430. This makes it roughly 190 times more transmissible than measles， which has an R0 of about 18.
“There are probably a lot of people in a population that may already be immune to a genre like electronica， because of their existing tastes，” said Rawson. “My nan， for example， is particularly resistant to the infection of trap and dubstep.”
If song popularity really is driven by the same contagious processes as disease， it could open new ways of predicting how new music releases could take off， and present opportunities to boost their spread.