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"The Door", produced by Block B's Zico and sung by WINNER's Kang Seung Yoon and Lee Seung Hoon, depicts the heavy, deep emotions of the characters spending their lives behind bars on top of a light, medium tempo beat. The OST is also unique in that Kang Seung Yoon, who is currently appearing in the drama as Jang Bal Jang, participated in as a singer. 

Listen to "The Door" above! Have you been watching 'Prison Playbook'?