Singer Tom Walker lauds Kate's piano skills after recording

Scottish singer Tom Walker praised the piano skills of the Duchess of Cambridge after the pair recorded a Christmas tune that was shown during a carol concert.

Walker, 30, performed a new song, "For Those Who Can't Be Here," accompanied by the 39-year-old Kate playing the piano, in a prerecorded segment shown during the concert broadcast on ITV on Friday.

Walker said he had kept the performance a secret -- even from his mother.

"She was in floods of tears watching it on the telly," he told the BBC. "It was beautiful."

Walker had performed at a charity event in front of the duchess, and when asked to play at the carol service he offered to perform a song the public hadn't yet heard.