In Japan, a geisha is a member of a professional class of women whose occupation is to entertain men. She must be adept at singing, dancing, and playing the samisen (a three-stringed musical instrument), in addition to being skilled at making conversation. The geisha system is thought to have emerged in the 17th century to provide a class of well-trained entertainers set apart from courtesans and prostitutes: though geisha sometimes had sexual relationships with clients, they were supposed to entertain primarily through their accomplishments. The numbers of geisha have declined from some 80,000 in the 1920s to a few thousand at present, almost all confined to Tokyo and Kyoto, where they are patronized by only the wealthiest businessmen and most influential politicians.