Songs of the Green Hills: An Anthology of Korean Sijos, Ch'ŏngguyŏngŏn, compiled by Kim Ch'ŏnt'aek and published in 1728, is the first and most significant anthology among the 170 extant ancient sijo collections. It contains 580 sijos, calssified by tune, writer, or theme. Kim gathered songs that had been passed down or scattered across the works of individual poets, then edited and published them, adding commentary not only from himself but also from other eminent writers. Songs of the Green Hills holds a pivotal place in Korean literature and serves as a foundational resource for the study of sijo. Additionally, this anthology was the primary source for gagok, a form of lyric song cycles accompanied by orchestra, when it was inscribed on the UNESCO Intangible Heritage of Humanity list in November 2010.Kim Ch'ŏnt'aek was a singer and sijo poet during the late Chosŏn period. Although he was likely born in the late 1680s, the exact dates of his birth and death remain unknown. He is also known by the names Paekham and Isuk, while his penname was Namp'a. It is recorded that he served as a p'okyo, an officer in the capital police, during the reign of King Sukchong. Kim is most renowned as the compiler of Songs of the Green Hills: An Anthology of Korean Sijos. In addition to his editorial work, he was a prolific sijo poet, having written 80 sijos, including 30 featured in the anthology.Won-Chung Kim is a professor of English literature at Sungkyunkwan University in Seoul, Korea, where he teaches contemporary American poetry, ecological literature, and translation. He has translated sixteen books of Korean literature into English including Because of the Rain: A Selection of Korean Zen Poems. Christopher Merrill has published eight collections of poetry, including Watch Fire, for which he received the Lavan Younger Poets Award from the Academy of American Poets. He directs the International Writing Program at the University of Iowa.