During the late 1960s Sandra Lang's career began under the HK English pop group named The Chopsticks. The group did not last long, as Lang soon went solo for TVB.
In 1974 her Cantonese TV theme song "The Yuanfen of a Wedding that Cries and Laughs" (啼笑姻緣) would make Cantopop the new music phenomenon. The song was aired on TVB Jade on 11 March 1974 at 7 pm. The 1974 version of the song was written by Joseph Koo.