Son Soo-gil (손수길) is a Korean pianist who played jazz in Seoul in the 1970s and is known today for one record: the quintet LP that Lee Pan-geun arranged for the producer Eom Jin (엄진), recorded in 1978 at a studio in Majang-dong, Seoul, and issued in February 1979. Discogs files him as Son Soo Gil (artist 4846732, with the Hangul variation 손수길) and, on the 2018 anniversary edition, as Sohn Soo-Kil, a separate entry (6878157). The 2013 reissue credits print Son Soo-kil, while the liner essay on the same release, and the Korean press write Son Soo-gil, the form used here.

Almost everything printed about him dates from the weeks around that reissue in October 2013. Tenasia, which covered it on October 25, 2013, wrote that he was little known even within Korean jazz but played superbly on the record, that he had been called a genius while still very young, and that through the 1970s he worked in the band of a saxophonist named Lee Jeong-sik (이정식). When Lee died, the article says, Son stepped away from jazz and joined the KBS orchestra, where he kept working as a musician. The liner essay of the reissue, signed by the DJ and critic Park Min-jun, agrees on the outline: it calls him a jazz prodigy who is better known as a regular member of the KBS orchestra, and says his way of playing jazz would have stayed a matter of oral tradition without this record. The two accounts are the only ones found, and neither gives dates for his years in the band or at the orchestra.

The bandleader is a different man from the living saxophonist Lee Jung-sik, born in 1961: the Hankook Ilbo, in its 2010 profile of Lee Pan-geun, calls the 1970s bandleader the late 이정식 and says that Lee Pan-geun played bass and wrote arrangements in his band. If it is the same bandleader, Lee and Son came to the 1978 session from the same bandstand, though neither article says so in as many words.

The record itself came from the pop side of the industry. Eom Jin, a producer who in the 1970s had made hits for Han Dae-soo, Yoon Bok-hee and other pop singers, asked Lee to put together an ensemble for a jazz record, and Lee chose the repertoire of Korean folk songs, pop songs and standards, with two of Eom's own songs among them. Lee gathered Kang Dae-gwan on trumpet, Kim Soo-yeol on tenor saxophone, Son on piano, Lee Soo-young (이수영) on bass and Choi Se-jin on drums, and the 2013 credits add Ryu Bok-sung on bongo. Discogs lists the 2018 edition with Ryu on percussion and Son under the spelling Sohn Soo-Kil. Seven tracks were cut, among them a ten-minute "Arirang", "Gasiri", "Han-o-baek-nyun" and a jazz setting of "My Favorite Things". The LP appeared as 재즈로 들어본 우리 가요 민요 팝송 (Dai Han AG-0003, with a cassette as AG-111) at a time when, Tenasia says, public awareness of jazz was weak, and it faded from memory. The critic Hwang Deok-ho passed a copy to Lee Bong-soo of Beatball Music around 2010, and Beatball reissued it in October 2013 as Lee Pan-geun & Korean Jazz Quintet '78, a name the unnamed band had never had; vinyl editions followed in 2015 and 2018.

What the people who made the record said about Son's part is the main evidence of what kind of player he was. Lee told GQ Korea in October 2013 that he made the record largely out of his expectations for Kim Soo-yeol and Son. He singled out the opening of "My Favorite Things", where the piano has to split the half beat or the phrase turns classical, and said Son played it exactly right, and he said Son played "Bin Ba-da" tremendously, with a melody that did not follow the chord changes and a very good touch. Lee recalled that Son was probably nineteen at the time and that the band called him McCoy Tyner; that is a memory from thirty-five years later, not a record, and no source gives a birth year. The reissue essay quotes Lee calling Son a genuine genius in an interview and hears unpredictable piano playing on the opening "Arirang".

Beyond the studio, the Hankook Ilbo's 2010 profile names the pianist Son Soo-gil among the players of Lee's monthly concerts at the Seoul jazz club Janus, which opened in 1978, beside Kang Dae-gwan, Choi Se-jin, the guitarist Cho Jeong-su (조정수), Kim Soo-yeol, the drummer Yu Yeong-su (유영수) and the singer Park Seong-yeon. The paper does not say how long he stayed. When Lee Bong-soo prepared the reissue he met Lee, Kim and Son in person to piece together how the session had gone, and he told Tenasia that Son, who had left the jazz world, still hoped to put out a jazz album of his own. No such album has been found.

Discogs files one more credit under the same entry: piano on four tracks of Kim Min-ki's debut LP 김민기 (Taedo EU 716, October 21, 1971), a folk record on which Jung Sung-jo arranged and played flute and saxophone. Only Discogs ties that credit to the pianist of 1978, and since Lee remembered the 1978 pianist as about nineteen, the player of 1971 would have been a child, so the link is unconfirmed.

What is not known is most of a life. No source gives his birth date or birthplace, his teachers, the years he spent in Lee Jeong-sik's band or at the KBS orchestra, or whether he is still living; the latest account, from 2013, has the reissue's producer meeting him in person. He has no recording under his own name, and no photograph of him has been found.

Only one record survives, so this section rests on what critics and Lee Pan-geun said about it. The critic Hwang Deok-ho, quoted by Tenasia, hears the modal jazz of John Coltrane's 1960s and the jazz-rock of Miles Davis's 1970s mixed unevenly, with Korean folk music running through both and the sound of the psychedelic pop recording of the day. The reissue essay hears the opening "Arirang" as a spiritual intro leading into jazz-funk drum breaks and a driving electric bass line, and compares it to labels such as Black Jazz and Strata East. Son's piano is the unpredictable element in that picture.

Lee's own praise concerns touch and rhythmic placement: splitting the half beat at the start of "My Favorite Things", and a melodic line that floats over changing chords in "Bin Ba-da". The McCoy Tyner nickname his bandmates gave him is the only named influence, and it is a nickname, not a statement of what he studied. Nothing else about his training or models has been published.