Jin of BTS will be lending his voice to the theme song of upcoming tvN series Cliffhanger (also known as Jirisan).Earlier today (October 1), South Korean news outlet Sports Dongah reported that production studio AStory had officially announced that the South Korean singer would be providing his vocals for the main theme song of the highly anticipated series.“BTS’ Jin’s song for the Cliffhanger OST will be the main theme song for Cliffhanger, and you will be able to hear it starting from midway