There was no fixed melody since it was originally sung by ordinary people, but fu (musical notes, note symbols) were chosen several times after it was introduced to the court as Outa (song), and incorporated into gagaku (ancient Japanese court dance and music), and two kinds of senpo, Japanese seven-tone gagaku scale (corresponding to: so, la, ti. do, re, mi, fa) ritsu and ryo were established in the mid Heian period.
元々一般庶民で歌われていたものであることから、特に旋律は定まっていなかったが、大歌として宮廷に取り入れられ、雅楽に組み込まれてから何度か符の選定が行われ、平安時代中期には律・呂という2種類の旋法が定まった。