Songs aren’t made like they used to be anymore. And that’s not just being said out of nostalgia by music critics who lived through the musical revolutions of the 1960s and 1970s. A study that analyzed the biggest musical hits in the United States between 1950 and 2022 confirmed this, using scientific evidence.

The researchers concluded that the melodies of the most popular songs are increasingly simple and repetitive. However, they clarify that this does not mean that today’s musical hits are worse or poorer musically, but that the complexity and richness in other elements, besides the melody, are less evident.

Madeleine Hamilton, lead author of a new study published in the journal “Scientific Reports”wanted to dedicate her doctoral thesis to this issue. When he started exploring melodies and analyze them, he first noticed that over the years the number of musical notes per second increased. And then he discovered something he wasn’t looking for: he saw that the parameters he used to measure the complexity of melodies had declined since the 1950s. That decade saw the triumph of songs like “Nel blu dipinto di blu” (Volare) by Domenico Modugnowhich topped the charts in the United States.

Hamilton wanted to confirm her serendipitous discovery and carried out a more thorough analysis, together with Marcus Pearce, her supervising professor at Queen Mary University of London.

Most research in computer science applied to music had been done directly from audio recordings of songs, which limited the study to very basic elements such as the rhythm of songs or the timbre of instruments. The analysis of these characteristics is now quite automated and, with the help of Artificial Intelligence, is used by streaming services – such as Spotify, Tidal or Apple Music – to recommend songs similar to the ones we listen to.

In order to go further and scientifically study something more abstract like melodies, Hamilton had to perform the painstaking task of transcribing the vocal part of the songs by hand. He did this during the first year of the Covid-19 pandemic, which coincided with the London lockdown.

After six months, he finally finished recording the notes and rhythmic structure of the most popular tunes of the past seven decades. Her catalog includes the five biggest hits of each year, according to the US Billboard Hot 100, which is based on record sales, radio airplay and streaming. He then refined and expanded the catalog, which is available online for public use and now covers the period from 1950 to 2022. It contains a total of 366 songs, with their melodic parts encoded in more than 1,000 digital files in MIDI format.

The researchers subjected all this material to statistical analysis, with algorithms to detect points of change. They came up with eight parameters that allow the melodies to be described with data. And through sophisticated computer calculations, they were able to confirm their original finding that melodies have become increasingly simple over the past seven decades. Furthermore, the researchers observed that in the evolution of melodies there are no cycles in which trends come and go. Instead, the decline in complexity has been a constant.

In their paper, the researchers also point out that there were two very sharp drops in melody complexity around 1975 and 2000. The researchers attribute this to the influence of new styles, such as disco music and hip hop, respectively.

However, the researchers stress that the scientific evidence does not mean that today’s big hits are worse than past hits. “Reduced complexity of melodies may be related to aspects of modern dyslexia”, the study states.

For example, melody is characterized by short pitch intervals and many repetitions, according to the study. This is evident in songs like “Bad Guy”, by Billie Eilishwhich reached No. 1 in the US in 2019. However, the researchers acknowledge that they still have a long way to go and that perhaps Artificial Intelligence will be the “key” to their research.