The third day of the platinum jubilee celebrations continues with a spectacular evening of entertainment. The concert at Buckingham Palace features a glittering array of global stars and performers from the worlds of music and dance to celebrate 70 years of HM the Queen's reign. As darkness falls, stunning projections illuminate the palace during the performances. Kirsty Young is in St James's Park in London with special guests, and backstage Roman Kemp is catching up with some of the performers taking part.