Pharrell Williams has surprised a British fan who thought she was just popping out for a quiet drink with a friend.

A clip released to promote ITV's Surprise Surprise sees 21-year-old Holly Addison and her best friend Lauren Hawke sitting in a pub during the afternoon when most of the rest of the clientele begin dancing to Pharrell's hit song Happy.

ITV explained: "Holly's father Gary died in February 2013 from an extremely aggressive form of brain cancer.

"Holly wanted to raise awareness of her father's condition and she has raised money for The Katherine House Hospice, Cancer Research UK and Brain Tumour Research."

Another "surprise" on the Holly Willoughby-fronted show sees a kind-hearted woman treated to a dinner date with Stephen Fry and a musical performance from Nicole Scherzinger.

The new series begins on Wednesday, 22 October.