A very cool video is going viral: The Australian cast of Disney's Lion King musical broke into a spontaneous rendition of "Circle of Life" Monday ... while on a plane. "After an amazing day at THE LION KING Brisbane season launch announcement, members of our Australian cast felt so elated they decided to sing the 'Circle of Life' prior to take off on their flight back to Sydney!" reads the video description on YouTube. The Daily Mail explains that the cast had just been in Brisbane to announce that they'd be touring there in September, and were on a Virgin Australia flight to Sydney, where they'll be performing through August, when they broke into song during the boarding process. (More The Lion King stories.)