The Week In Radio: When sex and the city make for a heady mix

One of the pet complaints of licence- payers, right up there with Jonathan Ross's salary and people who start their sentences with "so", is the idea that the BBC is too London-centric. 5 Live is relocating wholesale to Salford in an attempt to convince people that the BBC genuinely cares about the non-Oyster card classes. So I can only assume Radio 4 is aiming to correct any lingering London-envy with its current season celebrating the capital.

Anyone expecting the National Gallery and the Tower of London was in for a bit of a shock. The London season honed in on the reality of life in an overcrowded, multicultural city, and the Chelsea Flower Show this wasn't. File On 4, for example, had Jon Manel in a stab-proof jacket on immigration raids with the police. There are an estimated 200,000 illegal migrant workers in London and plainly the system depends on them, but these moving interviews illuminated the Canute-like task that immigration officers face. Brazilian Carl, who drives a van and has false documents like other people have loyalty cards, was a sunny optimist. "My life is very good, maybe I'm living here all my life. You working for one week you have big TV, one month you have car. All your dreams come true!" Felipe from Colombia, by contrast, was in tears. He came after the earthquake in 1999, hasn't seen his children in three years and even pays tax. "It's hard to be judged a criminal when all I'm doing is the best for my family. Is cleaning toilets a crime?"

Next up was sex workers. London Street Cries was an intriguing format in which voices from the 19th-century poor were contrasted with the underprivileged of modern London. And the undeniable result was that, although misery has continued unabated, the 21st century has injected some entrepreneurial variety into the oldest profession. One woman led us round her north London "work space", as proudly as any participant on a property programme. "We're sitting in the dungeon now, where I have a St Andrew's Cross because a lot of people enjoy restraint, and lots of things to hit people with, some of which are very painful," she said chirpily.

The admirably cool Catherine Stevens, "prostitute and dominatrix" who made the move from work in the voluntary sector, fretted that prostitution tended to be stigmatised. "Most of the people are really nice guys. They're my friends. Some of my family are not particularly thrilled about my work, that's fine. It's just not the right job for them."

And what else makes London special? Oh yes, knife crime. Over at London's Biggest Conversation, home of Nick Ferrari on LBC, they were debating victims and perpetrators of gang violence. "Let's be honest, they're nearly all black, though not all, before you call screaming at me," said Ferrari, in a stab at balance. Unlike, say, the Today programme, where a black gang member is as much a rarity as an elephant at the court of George III, Ferrari had a queue of people, parents of knife victims, and members of the black community, lining up to give advice on the topic. Typical was Connor who complained "these young people are so selfish. The only thing is to bring back National Service." Not so unlike the Today programme after all then.

Knife crime featured prettily heavily in the life of Edward the Third, focus of a wonderfully atmospheric Early Music Show on Radio 3. Sprinkled with motets and a lovely piece for mediaeval harp, this was an insight into a king who was "more responsible for the idea of England as a nation than anyone else is". After a troubled and blood-soaked childhood, Edward had 12 children, so according to the historian Ian Mortimer, "mathematically he's probably an ancestor of everyone of English descent living today." It was also Edward who made English our lingua franca. What would he make, you wonder, of the fact that there are now more than 300 languages spoken in London today?