Kelsea Ballerini & Arsenio Hall Bring Back "Greatest Hits"

YH goes behind the scenes of ABC's "Greatest Hits" with hosts Arsenio Hall and Kelsea Ballerini, who explain the concept of the show and talk about some of the show's epic musical pairings, including the Backstreet Boys and Meghan Trainor! We also chat with performer Gallant about his duet with Seal, plus we catch up with mastermind Ken Ehrlich and find out how LL Cool J and Wiz Khalifa saved the day!