Musician Tom Walker has opened up about practicing and performing with Kate Middleton for her Christmas carol concert at Westminster Abbey. Tom, who sang his poignant hit For Those Who Can't Be Here while Kate accompanied him on the piano, admitted the royal was understandable "quite nervous" in the first rehearsal.

Tom said: "I think the first rehearsal we did she was quite nervous because she hadn't played with another musician in a very long time. She's got a piano at home but the one that we'd rented in for the day was going to be the same one we were using for the actual service. It was completely different to hers, so she was trying to get the feel for that."

The Scottish singer-songwriter gave a personal insight into what the Duchess is really like, saying: "She's just lovely, really chilled out, very nice, seems really approachable and just really lovely. I was very nervous for the first five to ten minutes but I was all good after that."

The pair went through the song around nine times before recording the final performance, but Kate, 39, appeared to do even more practice at home in between their sessions.

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Tom said: "When she turned up for the actual performance, you could really tell she'd gone to town practicing because I was shocked at how much better she was. She really invested a lot of time and energy into getting it right and making sure that it was good, so I was really impressed – a great musician."