Otsuzumi and Kotsuzumi are drums used in Noh, Nagauta (dance music), geza and in traditional folk music. Their structure is similar but the otsuzumi is larger and has thicker heads. Heads, made of horsehide and attached to iron rings, are tightly laced to the cherry wood body. The heads are susceptible to humidity changes and heat may be applied to dry the hide or during the performance the kotsuzumi player may moisten the head with breath to adjust the drum's sharp tone. The kotsuzumi is held up to the right shoulder by the left hand which squeezes the rope while the right hand strikes the head in various ways. The otsuzumi is held in the left hand on the left thigh with the right hand striking the head.