EXO's 4th full album "THE WAR" has been released. The album contains a total of 9 tracks, including the title track "Ko Ko Bop". "Ko Ko Bop" is an energetic reggae song with rhythmical reggae and bass guitar sounds. Members CHEN, CHANYEOL and BAEKHYUN have participated in writing the lyrics, which talk about how to let your body move as it wants and dance freely together on the night before the inevitable war.