Melodies in hit music have become much less complex

Beyoncé performing on the Renaissance World Tour at Tottenham Hotspur Stadium in London on June 1, 2023. Source: Wikimedia Commons.

The idea that contemporary music can't hold a candle to its predecessors is probably as old as music itself. Music critics panned jazz when it first emerged in the early 20th century, and then rock'n'roll, punk, heavy metal, hip-hop, 2000s pop, and so on. With that in mind, whether today's music is better or worse than it used to be is a deeply subjective opinion – but that doesn't mean it's not different.

A new study from Queen Mary University of London seems to confirm what many of us have long suspected: melodies in modern chart-topping songs are less complex than in previous decades. The researchers believe the change in melody complexity may be due to the emergence of new music genres such as stadium rock, disco and hip hop.

However, this does not mean that modern music is less complex overall. Earlier popular music was typically released by bands with a handful of instruments that relied on vocals to create harmonic complexity, whereas today's music is more likely to be recorded in the studio and refined by many subtle layers and textures.

The researchers analyzed the top five hits on the US Billboard year-end singles charts from 1950 to 2022, including “Heartbreak Hotel” by Elvis Presley, “Hey Jude” by the Beatles, “Vogue” by Madonna, “Poker Face” by Lady Gaga and “Irreplaceable” by BeyoncĂ©. They used software that analyzed each song for characteristics related to pitch and rhythm.

The results published in the journal Scientific reports indicate a general trend of decreasing melodic complexity, with two major declines in 1975 and 2000, and a smaller one in 1996. The first major decline is attributed to the rise of stadium rock and disco music, while the 2000 decline can be explained by the rising popularity of hip hop music, known for relying heavily on looped samples. The mid-1990s decline can also be attributed to hip hop, although researchers also point out that it was around this time that digital audio workstations (DAWs) became popular. DAWs allow music producers to edit tracks and recordings on a computer. As computers became more widely available, so did the number of “bedroom producers,” some of whom went on to become professionals.

However, the study points out that this simplification of melodies is not the whole story. The analysis also showed an increase in note density, the number of notes sung per second, especially since 2000. This increase in note density can limit the complexity of melodies. If you have a melody with many notes per second, it in some ways limits the complexity of the melody because there is less room for other musical tones.

Interestingly, other studies have found no decline in the timbre or harmony of music over the past 50 years. This may be because other work focuses on other features of music and because the new study only looks at the chart-toppers. In fact, it seems that the most popular music is less complex overall, as a 2014 study found:

“We find empirical evidence that the instrumental complexity of individual styles has changed dramatically over the last fifty years. 'New Wave' or 'Disco' rose rapidly towards higher levels of complexity in the 1970s and then fell back to a low level of complexity shortly thereafter, while styles such as 'Folk Rock' have remained consistently at a high level of instrumental complexity.”

“We show that changes in the instrumental complexity of a style are related to its sales figures and the number of artists contributing to that style. As a style attracts a growing number of artists, its instrumental diversity typically increases. At the same time, the instrumental uniformity of a style decreases, that is, a unique stylistic and increasingly complex expressive pattern emerges. In contrast, album sales of a given style typically increase as instrumental complexity decreases. This can be interpreted as music becoming increasingly formulaic in terms of instrumentation once commercial or mainstream success sets in.”

Another similar study by the Spanish National Research Council used artificial intelligence to examine nearly half a million pop songs released between 1955 and 2010. The study concluded that pop music has become less melodically complex, uses fewer chord changes, and that pop recordings are being mastered to sound consistently louder (and therefore less dynamic), at a rate of about one decibel every eight years.

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