What makes something funny? Why do comics stand on stage in front of strangers and try to make them laugh? Is any subject beyond a joke? What is the purpose of Alan Yentob? Those questions – OK, only the first three – were raised by Imagine's presenter in this, the first of a two-parter about the art of stand-up.

You can see why prequels come into being. A dramatic character becomes a national treasure and eventually, once old age or worse removes them from the small screen, they are opportunistically exhumed by means of the backstory. Young Delboy was brought back to life in Rock and Chips. Young Morse is expected to be solving murders soon. And now here comes Young James Herriot.

“Will the app clicker replace the page turner?” asked Alan Yentob’s state-of-play rumination on the book. It’s a cutely phrased question and, as everyone reading this will be familiar with the digital world – this is theartsdesk, after all – a fair one. Will zeroes and ones make the book redundant, a sort of totem, or will it adapt, taking on the new forms presented by the digital world? The programme didn’t answer the questions, but at least it did show the possibilities.

That Alan Yentob gets around. I’ve run into him backstage during Jay Z's set at Glastonbury and in a jazz club in Poland, and here we found him in Rajasthan fronting a fascinating and well-shot programme, albeit workmanlike rather than really inspired, mostly set in one of the richest traditional music areas of India.

Steve Buscemi says he’s “from the country of Brooklyn”. In the wake of  Boardwalk Empire he could have said the empire of Brooklyn. Although the family history disinterred was genuinely strange, this first entry in the new series of Who Do You Think You Are? USA was no emotional roller coaster, mostly because of Buscemi’s low-key affability.

Garrow’s Law, which returned last night for a third series, would seem to be entirely about the foreign country that is Georgian England. One of its progenitors is Tony Marchant who, give or take the odd adaptation of Dickens or Dostoevsky, has spent his packed writing life in the modern day. But they don’t seem to make his kind of searing contemporary drama any more, the type that hunts for the root cause of moral failure in individuals and society. So in order to hold a mirror up to his audience, he has turned to the 1700s. Profitably.

“It’s very deep, very private and full of love,” said Art Garfunkel of his relationship with Paul Simon. So private that for this examination of their swansong 1970 album Bridge Over Troubled Water the pair were interviewed apart, despite both being credited as executive producers. Whatever the nature of the love, 40-plus years on, bridges weren’t being built.

What we're used to seeing whenever the BBC launches on one of its epic explorations of the natural world is moving pictures. But as well as training film cameras at their subects, from the largest mountains and glaciers to the smallest organisms, the hardy modern-day adventurers armed with their phenomenal hi-tech kit also train still cameras at everything they encounter.

Many commentators have professed bafflement at the tangled layers of Hidden, as it probed into a sick and murky past while apparently dead characters came back to haunt the present. Right to the end, writer Ronan Bennett kept his cards carefully concealed, so we still don't know who was really behind the sinister "Helpdesk" and its slick dial-a-killer operating system. Or at least it was slick at killing everybody except protagonists Harry (Phil Glenister) and Gina (Thekla Reuten), who somehow managed to wriggle away from their pursuers on a record-breaking number of occasions.

It’s been suggested that, come the revolution, the best possible of outcomes to the question of who shall be Head of State is the man off the goggle box who for innumerable aeons has been telling us about the birds and the bees, the silverbacks and the dung beetles, the fishes and the flytraps. But could we not, on reflection, do a bit better than that? If God does exist he is surely the spit of David Attenborough.