The Duke and Duchess of Cambridge were treated to a night of Gary Barlow hits when the royal couple joined thousands for a concert in aid of royal charities.
William is known to be a fan of dance acts and R&B tunes but when he met the X Factor judge he encouraged the singer to bring the house down.
The Duke and his wife chatted briefly with Barlow, minutes before he stepped out in front of a Royal Albert Hall audience, and were joined by the Prince of Wales and the Duchess of Cornwall.
Royal watchers were treated to a first as William and Kate, and Charles and Camilla had never attended a joint public event together.
The singer told the second-in-line to the throne: "I hope you enjoy tonight and I hope it's not too loud."
William, who wore a smart lounge suit like his father, replied joking: "The louder the better, the louder the better."
Kate looked relaxed in her black Ralph Lauren jacket and black and grey patterned Zara dress costing £69.99 and matched with a pair of boots, while Camilla wore an Anna Valentine jacket and dress.
When the royal couples took their seats in the royal box a huge cheer went up from the audience who got to their feet and the Prince of Wales acknowledged the reception by smiling and waving a programme in the air.
The event will raise funds for Charles's charity the Prince's Trust and the charitable body William runs with his brother - The Foundation of Prince William and Prince Harry.
See Gary Barlow with his royal guests, plus some other A-list attendees, in our Slideshow below...