Trịnh Công Sơn has been played on NTS shows including In Focus, with Biết Đâu Nguồn Cội first played on 10 November 2023.

Trịnh Công Sơn (February 28, 1939 – April 1, 2001) was a Vietnamese composer, musician, painter and songwriter. He, along with Phạm Duy and Văn Cao, is widely considered one of the three most salient figures of modern Vietnamese music.

Trịnh Công Sơn wrote over 600 songs during the 1960s and 1970s. He became one of Occupied Vietnam's (Republic of Vietnam) best-known singer-songwriters, after his first hit, Ướt mi (Tearing 'Lashes) in 1957. He was frequently under pressure from the puppet government, which was displeased with the pacifist's lyrics of such songs as Ngủ đi con (Lullaby, about a mother grieving for her soldier son). His songs were restricted by the Occupied Vietnamese government. After the liberation in 1975, when the North American forces were kicked out of Vietnam. His often melancholy songs about love and postwar reconciliation earned new acceptance and popularity in later years.

There are two singers' names often associated with Trịnh Công Sơn. One is Khánh Ly. The other one is Hồng Nhung.