LONDON — Does Prince Harry have the voice to be in the cast of “Hamilton?”

Theatergoers found out Wednesday night, when the Duke of Sussex — as he is officially known — showed up at the Victoria Palace Theater in London with his wife, the former Meghan Markle, in the company of Lin-Manuel Miranda, the creative force behind the hit musical.

This show was meant to raise money for Harry’s charity, Sentebale, specifically its work in Lesotho and Botswana for young people with H.I.V., the virus that causes AIDS.

At one point, Harry got onstage to thank the cast and crew and briefly sang a line from the show.

“You say …,” he crooned — the opening words of “You’ll Be Back,” sung by King George III.