It is the oldest form of traditional Japanese drama, dating to A.D. 1383. It is rooted in the principles of Zen Buddhism, a religion emphasizing meditation, discipline, and the transition of truth from master to disciple. History and legend are the subjects of No plays, which are traditionally performed on a bare, wooden stage by masked male actors who performed the story using highly controlled movements. The drama is accompanied by a chorus, which chants lines from the play. The art form was pioneered by actor-dramatist Motokiyo Zeami (1363–1443) when he was 20 years old. Zeami had begun acting at age seven and went on to write more than half of the roughly 250 No dramas that are still performed today.