The impact of hip-hop's arrival on the pop music scene eclipsed that of the Beatles-led British invasion of 1964, a computer analysis of 17,000 songs has found.
The unusual study found three revolutions on the charts: the 1991 emergence of rap and hip-hop on mainstream charts; the synth-led new wave movement of 1983, and the advent of the Beatles, Rolling Stones, The Who and other British rockers in the early 1960s.
Although the Beatles — paced by the songwriting of John Lennon and Paul McCartney — enjoy perhaps the highest place in critics' esteem, the researchers found the hip-hop movement — from pioneers like Afrika Bambaataa to megastars like Jay-Z — more profound.
They wrote that the rise of rap and related genres represents "the single most important event that has shaped the musical structure of the American charts in the period we studied."
By contrast, the British bands — heavily influenced by U.S. stars like Chuck Berry and Little Richard — were found to have followed existing trends.
That finding may trouble Beatles fans who think rock 'n' roll was invented with "Please Please Me" and "She Loves You." And it does not address why the Rolling Stones can still sell out arenas more than 50 years after they set the London club scene on fire with a British take on Chicago blues.
The study, released on Wednesday, was conducted by the University of London and Imperial College.
The researchers analyzed 30-second snippets of roughly 17,000 songs from the U.S. Billboard Hot 100 charts from 1960 to 2010.
Computer programs were used to categorize each song based on musical properties, instrumentation used, chord patterns and other elements.
Lead author Matthias Mauch said some may disagree with this scientific approach to a very personal subject but asserted the study breaks new ground.
"For the first time we can measure musical properties in recordings on a large scale," he said. "We can actually go beyond what music experts tell us, or what we know ourselves about them, by looking directly into the songs, measuring their make-up, and understanding how they have changed."
The authors claim the study provides "the basis for the scientific study of musical change" and could be used to provide useful analysis of music from other countries as well.
The study is not likely to be popular with aging musicians who peaked in the mid-1980s, which the researchers found to be the most static period in the study.
The authors also rejected the assertion that today's pop music is increasingly homogenized.
Scientific study: Beatles, Stones eclipsed by hip-hop impact