When Heike Monogatari, or The Tale of the Heike, is performed with a biwa, a Japanese lute, it is known as heikyoku or heike, which also refers to the vocals of kyōgen that imitate its verses. For example, the line ”ichi no tani no tatakai” in Genpei is typically performed quietly, with the horror of the battlefield expressed in comical lyrics. In zatō-mono kyōgen such as Kiyomizu Zatō, Saru Zatō and Mari Zatō, it is performed by the Kōtō and Zatō roles. Heike are also performed in the Ōkura School and Izumi School.