Keith Urban, the country superstar, is returning to American Idol as a guest mentor for one night only on May 21st during the show's season finale. The announcement was made via the show's official Instagram and Keith's own Instagram Stories. Keith will also perform his hit song "Wild Hearts" during the three-hour finale, according to Billboard. He was previously a judge on the show from seasons 12 through 15, beginning in 2012 when the singing competition was still on Fox. During the finale, Keith will mentor the top three contestants through their performances, leading up to one of them being named the newest American Idol.