Sir Ken Dodd celebrates his 90th birthday on November 8th 2017. He still performs regularly to sell out audiences around the country. As a ten year-old, fifty years ago, BBC Sports broadcaster Garry Richardson first saw Sir Ken perform and his fascination with "Britain's greatest comedian" began.

In this documentary made for Radio 4 Extra, the veteran comedian gives a fascinating insight into his life. He left school at 14 to help on his dad's coal round. Dodd explains how he went from performing with a teenage 'concert party' to a record-breaking run at the London Palladium. It's a career that was honoured this year at Buckingham Palace, when Sir Ken received his knighthood for his services to entertainment and charity.

With archive clips, What a Beautiful Day! features an extended interview with Sir Ken, as well as new interviews with Sir David Jason, Roy Hudd, Jimmy Tarbuck, Judith Chalmers and Sir Ken's script writer John Martin, who's been writing jokes for the comedian for over 25 years. All of them giving their own perspective on just what makes Sir Ken Dodd's comedy tick, at 90 years young and counting. The tattyfilarious Squire of Knotty Ash shows no signs of stopping just yet...