Study suggests that song melodies have become simpler since 1950

The complexity of the melodies of the most popular songs in the US – according to the Billboard year-end singles charts – has decreased since 1950, according to a study published in Scientific reports suggests.

Madeline Hamilton and Marcus Pearce analyzed the most distinctive melodies (usually the vocal melody) of songs that reached the top five spots on the U.S. Billboard year-end singles chart each year between 1950 and 2022. They found that the complexity of song rhythms and pitch arrangements decreased during this period, while the average number of notes played per second increased. They also noted two significant declines in melodic complexity that occurred in 1975 and 2000, as well as a smaller decline in 1996.

The authors speculate that the melodic changes of 1975 could represent the rise of genres such as new wave, disco and stadium rock. The changes of 1996 and 2000 could represent the rise of hip hop or the introduction of digital audio workstations that allowed audio loops to be played repeatedly, they add.

The authors point out that although the complexity of popular melodies appears to have decreased in recent decades, this does not mean that the complexity of other musical components – such as the quality or combination of sounds – has also decreased.

They speculate that the decrease in melodic complexity may be due to an increase in the complexity of other musical elements, such as an increase in the average number of notes played per second to prevent the music from sounding overwhelming to listeners. In addition, they suggest that the increasing availability of digital instruments may allow musical complexity to be expressed through sound quality rather than melody.

The results provide further insights into the development of pop music over the last 70 years.