Mathematical analysis of the relationship between notes reveals similarities with rock and pop
Jazz and Western classical music now resemble pop and rock more closely – at least to some extent. The melodic and harmonic structures of jazz and classical have become simpler with timeaccording to a mathematical analysis of April 23 Scientific reports.
“We are seeing an evolution in music,” says Niccolò Di Marco, a social and computer science specialist at the University of Tuscia in Viterbo, Italy. This change could be fueled by digital technologies, which make it easier to access and be inspired by recorded music.
Di Marco and his colleagues analyzed 21,480 musical pieces in six genres of Western music: classical, electronic, hip hop, jazz, pop and rock. The team used an audio file format, called MIDI, that encodes information such as the notes played, their timing, duration and intensity as numerical values. From there, they extracted data about the music’s melodies and harmonies and used it to map the relationship between notes, such as the order in which notes were played and which notes followed which. These networks allowed the team to visualize and analyze patterns.
Overall, the distribution of this data was more even across newer music genres, such as pop, electronica and rock. Older genres like jazz and classical music had more varied models. But when researchers tracked these trends over time, they noticed something interesting.
The first half of the 20th century saw quite complex structures in the field of jazz and classical music. Over the following decades, there was a trend toward repetitiveness in harmonies, intervals, and other structural features, more closely resembling the patterns exhibited by genres such as pop and rock. This, says Di Marco, “is a measure of how this piece explores possible musical space…following the rules of music.”
Having new technologies like digital audio and composition tools for musicians at everyone’s fingertips has changed the way modern musicians make music, Di Marco says. He also studied album cover trendsnoting a “broad shift towards minimalism”.
This does not mean that jazz or classical music becomes bland or loses quality. The paper is about the mathematical framework of music and not about the sound or listening experience, Di Marco and his colleagues say. There is much more to music creation, such as lyrics, production, sound design and cultural context. Modern music makers are simply finding “a different way to make good music,” says Di Marco. Much like album covers, this art form too is shaped and molded by cultural and technological evolution.
Cultural musicologist Friedlind Riedel agrees. Looking only at certain aspects could give the impression that there has been a loss of musical diversity, says Riedel, of the University of Salzburg in Austria.
“There’s always been a concern about music being simplified,” she says. “As in all arts, there is a long history of cultural pessimism, the idea of cultural grayness… However, the possibilities for musical listening have probably never been more diverse in history than they are today.”
