Derived from the ritual dances for rice-planting and harvesting and from folk entertainments such as acrobatics and juggling, Noh is the oldest extant professional theater in Japan. It was given artistic definition in the second half of the fourteenth century under the patronage of the Ashikaga Shogun. In Noh plays, only the leading character and his companions are masked. Other actors are unmasked but resolutely expressionless in their solemn performance of the musical drarna. The Kojō, or "old man," mask seen here, which represents the character of a small, wizened old man, usually designates a fisherman or a woodcutter. In theory, Noh masks obliterate the personality of the individual performer and lead to a more spiritual world.