Three years ago, the percussion troupe Etnobit visited Lake Baikal in eastern Russia in the middle of winter. There, the wife of one of the members slipped and fell. When she hit the ice, she made a loud booming sound. The drummers instantly recognized what that sound was: not a crash, but music.
They were very lucky. Other parts of the lake didn't produce resonant sounds when struck. It was only this particular spot where the water beneath the ice was shallow.
For 2 hours, they played on camera, striking different parts of the ice as only professional percussionists know how. The results are magical.