Alan Yentob presents the first of a two-part series for Imagine on the art of stand-up comedy. He talks to comedians in Britain and America, exploring their backgrounds and influences and their passion for making people laugh.

The second of a two-part series for Imagine on the art of stand-up comedy. Alan Yentob talks to comedians in Britain and America, exploring the evolution of stand-up and how it transfers to other mediums.