Jeong Cheol
Gasa (or Kasa) was a form of poetry popular during the Joseon Dynasty in Korea. Gasas were commonly sung, and were popular among yangban women. Jeong Cheol, a poet of the 16th century, is regarded as having perfected the form, which consisted of parallel lines, each broken into two four-syllable units. The form had first emerged during the Goryeo period.