This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
Sijo were composed to be sung, accompanied by court instruments, and the vocal setting shaped the form as much as any rule about syllable count did. One influential scholarly account traces the sijo's characteristic three-line shape directly to mandaeyeop, a slow court song style attested in fifteenth-century musical notation, arguing the poem's form followed the melody's rather than the other way around. The form's earlier history stays genuinely obscure: sijo are attested no earlier than toward the end of the Goryeo period, in the late fourteenth century, and some scholars place their emergence later still, in the Joseon Dynasty that followed Goryeo's fall in 1392; nothing in the surviving record pins the form's actual invention to a specific decade or a specific poet, leaving a real gap between when sijo must have existed and when the documentary trail can first confirm it did.