Taylor Swift and Prince William talk about noise levels ahead of her performance at Kensington Palace in aid of Centrepoint UK
William has also invited along Jon Bon Jovi - he did one of their songs in karaoke at cousin Zara Phillips' wedding - and James Blunt. Kate is on babysitting duty so there's no chance to see her next to some of the best known faces in the world at the moment. Unless they get really noisy in which case she might just pop down to tell them to keep it quiet or they will have to get Prince George back to sleep themselves.
She won't be laughing if she wakes Prince George up - Kate needs her sleep