Kakko (a Japanese percussion instrument) (羯鼓)
Kakko is a percussion instrument used in gagaku (ancient Japanese court dance and music), and it is a kind of tsuzumi (a long hourglass drum). The kakko is placed sideways in front of a performer, and the left and right sides of the kakko are beaten with drumsticks whose end is round like an acorn.
It was used in togaku (music from the Tang Dynasty China), and it controls the whole tune like a conductor. In komagaku (music from the Korean Peninsula), sannotsuzumi (a small double-headed drum struck on only one head) is used instead.