“Now, everybody wants to hear a melody,” crooned Billy Joel in the 1973 Barballad “Piano Man.” That may have been true when Mr. Joel was wearing young people's clothes, but new research from computational musicologists at Queen Mary, University of London finds that vocal melodies in popular music have gotten much simpler over time.
The study, published Thursday in the journal Scientific Reports, used mathematical models and algorithms to identify three “melodic revolutions”, in 1975, 1996 and 2000. These revolutions led to an increasingly simpler version of the two main components of melody: rhythm (the pattern of sounds and silences in a piece of music) and pitch (the measure of how high or low a sound is).
The study looked at the top five Billboard songs each year from 1950 to 2023. It found that rhythm and pitch have both steadily decreased in complexity over that time period. “Conservatively, they've both decreased by 30%,” said Madeleine Hamilton, a graduate student at Queen Mary University of Music who led the study.
Captain & Tennille's 1975 hit “Love Will Keep Us Together” is full of unexpected notes and complex rhythms.
A top song of 2000, Faith Hill's “Breathe” has no accidentals, is highly repetitive, and has a straightforward rhythm.
The simplification of melody is not a new concern for some musicologists—”melody's status as one of the fundamental building blocks of music has been greatly diminished,” composer Yuval Shrem wrote in a 2014 Keyboard article cited in the study—but the new research adds rigorous quantitative evidence to support the trend.
Hamilton and her supervisor, Marcus Pearce, leader of the Music Cognition Lab at Queen Mary University of the Arts, found that other aspects of popular music, such as the number of notes played per second, have actually increased over time, suggesting that the loss of melodic complexity represents a kind of trade-off. This change may be due to technological advances.
“Today, with the availability of digital music production software and libraries of millions of samples and loops, anyone with a laptop and an internet connection can create any sound imaginable,” the researchers wrote.
In interviews, they warned against making value judgements about the loss of melody, because they said the tendency could easily fall victim to a culture war narrative about classical versus contemporary music.
“It's not that the music is getting simpler,” Hamilton said. “The melodies are getting simpler, but the chords and compositions may be getting more complex.”
Melodies tend to be pleasing to the ear, which is why we hear Ludwig van Beethoven's “Symphony No. 5” or the opening lines of Lady Gaga's 2008 hit “Poker Face.”
“Melody is often the most obvious potential heart and soul of a piece of music,” says composer Oskar Osikki, who runs the music YouTube channel Inside the Score. “It draws us in, evokes emotion, and makes our souls dance along its contours.”
Hamilton began studying melodic aesthetics in preparation for her dissertation in 2019, but then encountered a shortcoming that would define her career for several years. “I realized that all the data sets available were classical and folk music, and I thought that was kind of weird,” she says. “It's not representative of the music that people listen to every day.”
Hamilton decided to create his own dataset using the Billboard Melodic Music Dataset, which contains 1,131 melody files for the top five Billboard songs for each year from 1950 to 2022. (Hamilton himself uploaded a selection of last year's hits, including Morgan Wallen's “Last Night.”)
She listened to all 366 songs in the database and transcribed the vocal melodies (about three per song) into the online music notation program MuseScore.
At the time, London was under lockdown to prevent the spread of COVID-19, and Hamilton spent most of her time alone in her dorm, listening to melodies for 10 hours every day. She is still recovering from that experience and doesn't listen to much pop music, but no song has stayed with her as much as UB40's cover of Elvis Presley's “Can't Help Falling in Love,” which hit No. 3 on the Billboard charts in 1993.
Hamilton measured eight melodic metrics, four rhythmic and four pitch-related, for each melody in each Billboard song in the dataset. These include the number of notes per measure and the average melodic interval between successive pitches, for example. Roger Dean, a molecular biologist, musicologist and composer at the University of Western Sydney in Australia, offered key advice, along with what Hamilton calls a “sanity check.”
Hamilton also used a statistical model developed by Dr. Pierce to measure how predictable each melody was, both in terms of rhythm and pitch. “The model 'guesses' what note will come next in the melody, based on the notes that precede it,” Hamilton said. “It then gives a value that represents how 'surprised' the model was, on average, throughout the melody.”
Hamilton then used an algorithm that linguists have used to study changes in language use to uncover the timing of key moments in pop music's evolution. She found that there was a sharp drop in melodic complexity in 1975, around the time disco and stadium rock took hold. That was followed by a somewhat more gradual drop in 1996, when hip-hop and electronic music grew in popularity and MTV took off. The year 2000 loomed another significant melodic cliff, likely the result of the same forces at work throughout the 1990s.
Digital culture, including social media, may have accustomed people more broadly to smaller chunks of information: “Our brains are so accustomed to reading and writing fragments to fit various digital character limits that they no longer expect, need, or crave complete sentences, musically or otherwise,” Shrem wrote in a 2014 Keyboard article.
Pharrell Williams' “Happy,” the number one song of 2014, was characterized by high production values but low melodic complexity.
But some say it makes sense to move away from melodic variety, given that the human brain has a limit to how much complexity it can handle. Patrick Savage, a musicologist at the University of Auckland in New Zealand, says the spread of digital tools and cultural changes have allowed music to innovate in some ways, but at the expense of creative nuance in others.
“You can't enjoy something that's too complex to understand, remember or reproduce,” he said. “There are certain limitations there.” Dr. Savage added that one limitation of the new study is that it can't fully account for the unique complexities of rap music. “Western musical notation is not designed to capture the microtonals of rap speech, and in some ways, rap microtonals are more complex than a typical song melody,” he said.
Hamilton agreed that melodic complexity is not an indicator of musical quality: “Simplicity has its own beauty,” she said.