Before dawn Saturday, thousands of revelers will again gather among the monoliths at Stonehenge to sing, bang drums and frolic beneath a solstice sunrise.

Theories surrounding the monument’s intended purpose — temple? observatory? big sundial? — go in and out of fashion. But this year, the partygoers will show up outside Salisbury, England, with fresh evidence that the site was always intended to host such shenanigans.

Specifically, making loud rock music.

Researchers from the Royal College of Art in London have found that some of the monument’s rocks possess unusual acoustic properties; when struck, they make a loud, clanging noise. Perhaps, they say, this explains why these particular rocks were chosen and hauled from nearly 200 miles away — a significant technical feat some 4,000 years ago.

Could it be that Stonehenge was actually a prehistoric glockenspiel?

“People say, ‘Why did they bring the bluestones to Stonehenge?’ ” said Paul Devereux, an author of the study and editor of the journal that published it, Time and Mind: The Journal of Archaeology, Consciousness and Culture. Indeed, scientists have long known that many of the Stonehenge rocks were taken from the Preseli Hills, in West Wales. What was never clear is why.