The Country Show With Bob Harris

Radio 2, 9pm

On August 19, 1970, Harris (right) made his debut on Radio 1. Now he’s celebrating 50 years on air in a special programme featuring some of his favourite tracks, as well as live music from Mary Chapin Carpenter.

In The Infinite Monkey Cage (Radio 4, 9am & 9.30pm), Brian Cox and Robin Ince are joined by Mark Gatiss, Carlo Rovelli and Fay Dowker to ponder the nature of time and whether it exists within the laws of physics.

In Business (Radio 4, 8.30pm) asks if the Black Lives Matter movement will lead to increased investment in black-owned companies.