Will.i.am and Sean Lennon rubbed shoulders with Prince Harry at a glamorous bash in New York.
The royal was the star of a fundraising dinner in aid of US supporters of Prince Harry's Royal Foundation.
The third-in-line to the throne proved a draw to Sean, son of Beatle John Lennon, The Voice judge Will and writer John McInerney, who penned Bright Lights Big City, at Manhattan's famous Four Seasons Restaurant.
Black Eyed Peas star Will.i.am said: "I am a fan of how Queen Elizabeth raised her children and how they have raised their children.
"I am a great admirer of Prince Charles and his charity work and I think it is incredible Harry has made it part of his legacy to carry this on. He doesn't have to do what he does, so I applaud him."
Will met the Prince after last year's Diamond Jubilee concert at which he performed.
He added: "He's a party prince, a soldier and a philanthropist. He's a regular guy. If Harry was a movie character he would be Iron Man.
"I grew up watching documentaries about the royal family so I am really pleased to be meeting him."