In Ze’ami’s treatises on Noh, an actor who has reached the highest level of his craft is said to have “blossomed” (ran is the Japanese for orchid), and the rangyoku is a set of vocals dedicated to this position. Ze’ami placed vocals into five categories: celebratory, mysterious, love, sorrow and rangyoku, or “blossoming,” with rangyoku considered the highest and superior form. Rangyoku may also refer to the performance of selections from older plays by a single performer. There are around 50 plays including Asukagawa, Kashii, Shimami, Hatsuserokudai and Tōgokukudari, which required the highest level stage and technique, and as such are rarely performed.