The pop star known for the songs "Do Ya Think I'm Sexy" and "Maggie May" will perform at a party Charles' wife, Camilla, is giving Saturday at their Highgrove estate.
It's the latest celebration in a festive week for the prince, who turned 60 on Friday.
It began with a comedy performance on Wednesday. His mother, Queen Elizabeth II, held a dinner party and concert at Buckingham Palace on Thursday. On Friday, Charles was honored with cannons booming a 41-gun salute across central London, at Hyde Park, and with a celebration with young people, sponsored by his charity. He skipped the Hyde Park salute to go to the charity event. He was also scheduled to attend a children's concert at the Royal Opera House.
But amid the hoopla, the omnipresent question remains, will Charles ever ascend to the throne and become king?
He's already the longest monarch-in-waiting in British history.
Do Britons really want him on as king, or would they prefer he be passed over in favor of his popular son, Prince William?
"Evybody is sort of saying, 'What's going to happen now for him?' longtime royals-watcher Neil Sean pointed out from London on The Early Show Saturday Edition, "and I think the bottom line for him is that he just wants to enjoy his life. You know, everybody is saying, 'Will he become king?' Well, yes, he will become king, but not in his time, until the queen decides.
" ... As everybody knows here in England, her majesty the queen has got no plans to abdicate, to move over, to even retire," Sean told co-anchor Chris Wragge. "It's just not a word that would be associated with the queen, and Prince Charles knows this.
"What we can tell you is that Prince William (the eldest son of Charles and the late Princess Diana) has no desire ... to sidestep Prince Charles and take over from the queen. You know, Prince William openly admits he wants his father to have a crack at the job, as they say, and Prince Charles would be ready.
"Earlier this week, Her Majesty stated on TV that Prince Charles would make a fine king, so she has given an endorsement, but it's not the sort of job [you can just make your way into. Something bad would likely have to happen to the queen first]."
How popular is Charles in Britain?
"Ten years ago," Sean said, "after the sad loss of Diana, etc., his rating was very low, but he slowly built it back up. We have to say that's partly due as well to Camilla, his wife. She's a great supporter of Prince Charles, whatever you may think. I think without her, it would have been a longer and harder battle for him to win the approval of his subjects. His rating here is very high right now, and I think, particularly over the last couple of days, this documentary (about Charles at 60, on the BBC) has warmed Britain to the fact that, in fact, Prince Charles is a very nice person. Remember, he used to talk to plants, and he talked about being organic!"