According to an exclusive report by Star News on January 6, CL wrote “GOOD BYE,” and musicians J Gramm and Rock Monroe composed the song. Rock Monroe most recently worked as a composer for the song “Desperado” in Rihanna’s “Anti” album.
The report states that “GOOD BYE” was originally a song for CL’s solo U.S. promotions, written by CL as an outlet for the leader’s feelings of regret about the end of 2NE1. However, YG Entertainment thought it would be a good song to release as 2NE1 for Blackjacks, and contacted Sandara Park and Park Bom to meet for one last time in the recording studio.
https://www.soompi.com/2017/01/05/st...inal-good-bye/