Mathematicians discover music really can be infectious – like a virus

Pop music is often described by being catchy. But, it seems that you can really infect your friends with your music taste. The download pattern for music after its release seems to closely match epidemic curves for infectious diseases. Electronica seems to be the most infectious type of music.
Dora Rosati (lead author of the study) was a former student in statistics and maths at McMaster University in Ontario. She and her colleagues wondered if they could find out anything about songs' popularity using mathematical tools that are more commonly used to study the spread infectious diseases.

The team used a MixRadio database that contained almost 1.4bn individual songs downloaded from the now-discontinued streaming music service MixRadio. They examined the top 1,000 songs that were downloaded in the UK from 2007 to 2014 and compared how the SIR model (a standard model of epidemic diseases) reflected trends in song downloads over the time.

The research was published in Proceedings of the Royal Society A. Mathematical and Physical Sciences. It found that the model performed equally well when it described song download trends, as when it described the spread of a particular disease throughout the population.

Rosati stated: It suggests that many of the social processes driving the spread disease or analogues might also be driving song spread. It supports the notion that music and infectious diseases are dependent on each other's social connections for spreading through their populations.

If you are exposed to someone with a disease, you may contract it. It is very similar with songs. It is important to note that songs don't have to be physically touched. My friend could have posted this song on their Instagram story. I will now go find it.

Dr Thomas Rawson is a London-based disease modeller. He said, "It makes perfect sense when you consider that wordof mouth is something that, similar to disease, will continue via other people." There are many ways music can spread.

Rosatis team also calculated basic reproduction number (R0), which is a rating of the disease's ability to spread. This assumes that the population has no immunity from infection or vaccination for various music genres.

Although the results varied between genres, they found that metal and dance had the lowest median R0 scores of 2.8 and 3.0 respectively. While pop music was more transmissible than other genres, it was greatly outstripped in the case of rock and hip-hop. Electronica, a form electronic music that is intended to be listened to rather than dance, had the highest R0 at 3,430. It is approximately 190 times more transmissible that measles (which has an R0 around 18.

This does not mean that electronica music is downloaded more often; it just means that there is a greater spread to the wider audience.

Rawson said that diseases are limited in their spread through physical contact. Rawson said that songs might have high R0s because you can send a single tweet and infect a hundred people. A song disease can be spread much faster than an infectious disease.

Rawson said that there are likely to be a lot more people who have already been exposed to electronica because of their tastes. For example, my nan is resistant to trap and dubstep infections.

Rosati stated: Perhaps these numbers show that electronica lovers tend to be more passionately about their favorite songs. Or, maybe electronica fans are more connected.

She also suggested that pop music, which is more mainstream, could spread more easily through passive media like radio.

Transmission rates could also change over time. Rosati stated that radio was still the best way to transmit pop and rock music back when it was the primary transmission method. These niche genres, which may not have received the radio airplay or were not as popular, will likely see the biggest changes. They have a better chance of spreading with streaming and social media.

If the popularity of songs is really driven by contagious diseases like disease, this could lead to new methods for predicting how new music will take off and offer opportunities to increase their spread.

Rosati stated that mathematical models of disease spread can be used to determine things such as the average time it takes for an individual to become infected, the size of an epidemic or the duration of an epidemic. We might also be able use these models to find out how long an individual will listen, how many people will download the song, and how popular a song might be.