Set to happen at the start of Sunday's show, Charles and Camila's surprise appearance on the long-running singing competition series comes just hours after both Perry and Richie performed at the king's While Richie got Charles on his feet with his hits,"Easy " and"All Night Long," Perry had Ahead of the special concert, "I'm grateful I get to go.
"So I'm also an ambassador for UNICEF, and it really aligned with my values. That's mostly why I'm going, to be an ambassador and to say, 'Hey, this is me from the USA.' No, but it's so cool," she added."I mean, first of all, when you've been in the business a long time, and, of course, when you get an invitation like this, the answer is absolutely," .
Guest judges Alanis Morissette and Ed Sheeran are filling in while Richie and Perry make their way back from the U.K. Morissette is also serving as mentor for the Top 8.RELATED CONTENT: