Used in contrast to genkōkyoku, plays currently being performed, haikyoku refers to plays no longer being performed. There are around 200 genkōkyoku in the major schools of Noh, and in their shadows are and immense number of haikyoku, which have come and gone over long history of Noh. Among haikyoku which haven’t been performed in quite some time are some plays which would require research to actually perform, and some which could be performed right away as their lyrics, katatsuke, and tetsuke of the music are still known. Replaying haikyoku is known as fukkyoku, or a “revival performance.”