In the wide-sense, the drum is something with a mounted skin struck in some ways to emit sound, thus, it includes all the drums ranging from the uchiwa-daiko (a round fan drum) recognized by the aborigines in Asia, the Native people in Asia, the drum struck in the Nichiren sect, to the hand drums used for the Noh music.
何らかの仕方で張った皮を打って音を出すという広義の理解ではアジアの先住民に認められる団扇太鼓（日蓮宗の打つ太鼓）から能楽に使用する鼓類までを含んでしまう。