Goryeo Gayo (고려 가요, 高麗歌謠)

The term 'goryeo gayo' collectively refers to the folk-song like poems of the Goryeo period. These songs are called by several other names too, like the abbreviation, yeo-yo (여요, 麗謠) or goryeojangga (고려장가, 高麗長歌). In a broader meaning even hyangga poems, folk-songs and buddhist songs can be called goryeo gayo, but in a stricter sense, goryeo gayo is the collective name of gyeonggichega (경기체가, 景幾體歌, didactic poems from the late Goryeo period) type poems and sokyo (속요, 俗謠, 'popular songs').

Goryeo gayo was an extremely popular genre, its topics were mostly love, parting, and longing for a loved one. These songs are characterized by the use of lines without meaning, often in the form of a refrain. Its creators were mainly from the lower social classes.  

Goryeo gayos circulate through oral tradition and were only recorded in the Joseon period. However, the strict Joseon censorship filtered out many goryeo gayo songs and did not record them because of their topic (mostly the realtionship between men and women), so many works were lost.