The advent of Western influence has brought about many changes to Korean music. The most significant were the division of Korean musical culture into kugak (traditional Korean music) and yangak (Western music) and the rise of a new genre, ch'angjak kugak, "new compositions for traditional music". Kim Kisu, who was trained as a traditional court music performer in the early 20th century, was the first modem composer of music for traditional instruments. His music was written in staff notation incorporating various Western elements, including harmony, diatonic scales, and playing techniques based on Western instrument practices. Though he was trained as a court musician, his works demonstrated a desire to embrace Western culture and music in his compositions. Since Kim Kisu's innovations, many composers have been influential in the development of the genre. I focus on two of the most representative, Yi Sung-Chun and Yi Haeshik. Yi Sung-Chun, who is also a highly respectable educator, has sacrificed his musical life to expand the quantity and the quality of this genre. In the 1980s, he designed the improved 21-string kayagüm and has written significant and successful pieces for this instrument. His search for new sounds led him to break many of the old conventions surrounding traditional instruments, and to write more contemporary and modern music. Yi Haeshik, who is known for his use of the folk idiom in his works, has composed many pieces that borrow elements from traditional shamanistic music, sanjo, folksongs and more. His approach reflects a movement to find "Korean contemporary identity" within the folk tradition in Korea and other countries, and within the world of dance. The ch'angjak kugak genre has seen significant development in the years since its inception and the three composers I focus on - Kim Kisu, Yi Sung-Chun and Yi Haeshik - best demonstrate the progress of the genre