%%Discovered by the French in Đắc Lắc in 1949, Đàn đá (Lithophone) is an ancient musical instrument with 11 slabs of stone. Later, four more Đàn đá were discovered in Sông Bé and Khánh Hoà. It results from the researches that Đàn đá existed between 4,000 and 10,000 years ago.