Chimpanzees drum with non-random rhythms, according to new research that suggests the building blocks of music may have existed millions of years before humans evolved. The study, published in Current Biology, analysed 371 drumming bouts from 47 chimpanzees across six populations of two subspecies—eastern and western chimpanzees.
Researchers found that all chimpanzees drummed with predictable timing, indicating a sense of rhythm. However, the two subspecies displayed distinct rhythmic styles: western chimpanzees produced evenly spaced beats, like a ticking clock, while eastern chimpanzees alternated between shorter and longer intervals, creating a swing-like pattern. Western chimpanzees also used more hits per drumming bout, suggesting a faster tempo.
Lead author Vesta Eleuteri and senior author Professor Catherine Hobaiter of the University of St Andrews noted that the differences were not linked to ecological factors. Instead, they may relate to social behaviours, such as the higher levels of aggression observed in eastern chimpanzees or the need to convey more information through variable rhythms.
“When you’ve got more variable intervals—those long, short, long shorts—you might be able to encode a bit more information, in the same way as Morse code,” Hobaiter explained. The team emphasised that while chimpanzees do not produce human-like music, their drumming shares fundamental rhythmic properties, pushing back the evolutionary origins of rhythm by several million years.
“Before humans were human—six, seven million years ago—the apes that were roaming around that eventually would evolve into chimpanzees and humans probably had some basic building blocks of rhythm,” Hobaiter added.
