Sin Jae-hyo (1812–1884), a native of Gochang, systematized pansori — until then transmitted only through oral performance — into six madang: Chunhyangga, Simcheongga, Sugungga, Heungboga, Jeokbyeokga, and Byeongangoe taryeong, and set the lyrics down in pure Korean script. He was also the theorist who established pansori's four core principles: character, narrative, vocal mastery, and stage presence.
A story passed only by mouth inevitably drifts as it moves from performer to performer, generation to generation. What Sin Jae-hyo did was give that drifting story a system for the first time. Once it passed through his hands, pansori gained the footing to grow into a literature that crossed class lines — and the standing to be handed down intact to the present day.