Issei, or “one voice,” is a short vocal sung directly after the entrance of the shite. They are often sung out of rhythm in a calm manner. The hayashi’s performance of the flute, kotsuzumi and ōtsuzumi upon the entrance of ghosts and spirits is also known as issei. Using the Noh play Ukai as an example, after the isseiof the hayashi upon the entrance of the maeshite, the issei, “How shall we pass the dark road following the bonfire on the cormorant fishing boat?” is sung. The issei is also used in kyōgen as simplified or imitative versions of those in Noh .