This study aims to discuss changes in gyemyeon-jo, and furthermore, examine the post-mode phenomena of the existing gyemyeon-jo style. This is a somewhat complicated issue in that changes in gyemyeon-jo can’t be discussed merely in terms of changes in musical scale as there are differences in phenomena that arise depending on different pieces of music. The discussion on changes in gyemyeon-jo was developed focusing on four pieces of music, including Yeongsanhoisang, Jeongdaeeop, Sujecheon and Pungnyu-daeseureum, and by considering the fact that gyemyeonji exhibits complicated elements particularly in court music and pungnyu. The results of the discussion conducted in this study are as follows. It is presumed that gyemyeon-jo began to change in the early 18th century and phenomena associated with this change were diverse depending on different pieces of music. Yeongsanhoisang Sangyeongsan changed to pyeongjo in about late 19th century as taeju, instead of tones of gyemyeon-jo, was used. This development or circumstance is also confirmed in Pungryu-daeseueum, the fourth movement of Sujecheon. Not all musical pieces of gyemyeon-jo changed to the trichord-tetrachordscale. In Sujecheon, the gyemyeon-jo pentatonic scale was maintained. Jeongdaeeop features the tetrachord scale of Takmuyeok-Hyeopjong progress, but the trichord scale was formed with ‘Takmuyeok(㒇)-Hwangjong(黃)-Hyeopjong(夾)-Jungnyeo(仲)-Imjong(林’) and changed to pyeongjo. Regarding musical pieces, such as Yeongsanhoisang Sangyeongsan, Sujecheon, Jeongdaeeop and Pungnyu-daeseueum, their original gyemyeon-jo nature was changed because scale instead of tones of gyemyeon-jo, was used, and a trend where in gyemyeon-jo was considered the same as the post-mode appeared, via a procedure whereby the scale was changed from pentatonic to trichord or tetrachord.