The Den-den daiko (でんでん太鼓, lit. "denden [double-ended] Drum") is a Japanese hand-held pellet drum, used in Shinto-Buddhist ceremonies, etc.
It has two heads and is suspended on a rod, with beads or pellets hanging on threads on either sides of the body of the drum. The drum sounds when it is turned on its axis from side to side, causing the beads to strike the heads of the drum. It is similar to the Chinese pellet drum.
