shirabyoshi (literally, White rhythm) (白拍子)

Shirabyoshi is a type of singing and dancing performance developed from the late Heian period to Kamakura period. It also refers to an entertainer who performs such. A prostitute disguised as a man dances while singing an imayo (contemporary pops) or a roei (Chinese poem recitation). It is also written as "plain rhythm" and in this case, it means an improvised dance without any accompaniment.

Many Shirabyoshi are mentioned in "The Tale of Heike" (The Tale of the Taira family), a war chronicle written in the early Kamakura period, and they are described as follows. "The origin of Shirabyoshi is thought to have been when two women (Shima no Sensai and Waka no Mae) started to perform dances dressed as men at some point during the reign of the retired Emperor Toba." "Because a suikan (a plain kimono worn by worn by male court nobles) and a tate-eboshi (a tall, upright type of formal headwear worn by male court nobles) were worn together with a shirosayamaki (a sword decorated with a vine or a similar material in a sheath with a silver fitting), it was called otoko-mai (a male dance) at first."
"Later, when the tate-eboshi and a sword were no longer used and the performer wore only a suikan, the performance became known as shirabyoshi (white rhythm)." (Excerpts from the chapter in "The Tale of Heike" called 'Gio'.)

Summary

Shirabyoshi is a dance irrespective of gender, however, it is often danced mainly by women or children.

The history of shirabyoshi can be traced back as an original dance performed by shrine maidens. In Shinto rituals, men and women kannabi (people who serve and sing to invite the gods) dance from the old days, thus, when a kannabi is possessed by god, there may be occasionally cases where the gender is temporarily switched. When YAMATO Takeru no Mikoto conquered Kumaso (a tribe living in the ancient Kyushu district), he dressed himself as a woman, and when Empress Jingu conquered sankan (three countries in old Korea), she dressed herself as a man, that symbolized the moment when they are possessed by god.

Afterwards, shrine maidens traveled on foot to propagate religion and performed the dance, then it changed gradually to the performing arts of prostitutes who were influenced by the tradition of a shrine maiden disguising as a man, who excelled in dancing like a man were generally called shirabyoshi.

They wore hitatare (a jacket with a neckband directly and vertically sewn which is worn together with hakama, a long pleated skirt worn over a kimono), or suikan (a costume for males made of simple cloth), wore the headgear of court nobles, held swords with white rolling sheaths, and presented their songs and dances, while disguising themselves as men (as time went by, it was quite often that they wore costumes with color). For accompaniment, tsuzumi (Japanese hand drums), and sometimes pipes (or flutes) were used.

Later, it was transformed into sarugaku (one of performing arts that includes funny mimicry and speeches).
Then, it paved the foundation for soga (kind of song and ballad which were popular among nobles, samurai, and Buddhist priests from the mid Kamakura period to the Muromachi period), and kumasei (a performing art of singing with a tuzumi and dancing with a fan, popular from the period of the Northern and Southern Courts to the Muromachi period.)
Moreover, it was taken in celebration of longevity and it continued until the early Muromachi period.

Even though women who danced shirabyoshi were prostitutes, because they often visited noblemen's residences, they were often discerning people, they were often shirabyoshi who were loved by some men of high social position and great fame; examples include Gio and Hotoke-gozen, who were much-loved mistresses of TAIRA no Kiyomori, and Shizuka-gozen, who was the much-loved mistress of MINAMOTO no Yoshitsune.