"Kate asked what kind of music I'd been playing," Corporal Steve Johnson, an RAF recruitment officer from Newcastle, who is busking at Tube stations across London told the Press Association. "She asked me to play but then said don't because it's too busy.
"Kate was more interested in the music, while William was more concerned with the day itself and how the appeal was going. Lots of people are ecstatic to see them."
More top news
Twins Laviai and Lina Nielson were so inspired by volunteering at London 2012, that their ambition ever since has been to compete at Rio.
Candidate Sadiq Khan called for Ken Livingstone to be thrown out of the party after the former mayor claimed Hitler supported Zionism.
Police are hunting for a passenger seen on the Victoria Line after a woman was sexually assaulted on the Tube.