Excavations in Bulgaria have yielded several hollowed-out bone dance rattles capped with thin sheets of hammered copper. Dating to the late Neolithic period, these instruments are among the earliest examples of metal-enhanced musical tools in Europe. Wear patterns on the handles indicate they were used in prolonged, rhythmic dancing during spring planting festivals.
The combination of bone and copper suggests a symbolic union of the earthly and the celestial. Researchers believe these rattles were intended to summon rain and ensure soil fertility, marking a significant milestone in the evolution of communal ritual performance in the Balkan region.