The theme music for The Reunion belies what is to follow. That plinky-plonky snippet of Liszt – Dieuxieme Annee III, Canzonetta del Salvator Rosa – is all smiley, dainty and light. And yet the show, with its simple idea of reuniting a group of people closely connected to a significant moment in history, is anything but. Like Desert Island Discs, which it replaces in the schedules when it is off-air, the format here quietly encourages an intimacy and frankness from guests. And as with Desert Island Discs, it is The Reunion's presenter that is key to the programme's success. It's hard to imagine anyone else bettering Sue MacGregor with her familiar taut voice and impeccable manners – she doesn't talk over guests or rile them, but politely nudges them to talk with simple, open questions ("What happened next?"). The result is an elegant, intelligent format and tone, and one of the best programmes on Radio 4. One of the ingenious aspects is the eclectic mix of historical moments selected. This is a programme that might feature the Hillsborough disaster in one episode, Play School in another, and makes brilliant radio out of both. It covers hard news stories exceptionally well – the Iranian embassy siege; the release of Nelson Mandela; the IRA bombing Brighton's Grand Hotel – but also softer news, arts and sport. Vintage episodes of this ilk include the making of Withnail & I and, more recently, the 1948 London Olympics. But the best, most memorable, programmes are those that have opposition at the core as well as a shared experience. Last year's Fall of Barings Bank programme, in which Nick Leeson faced his former boss for the first time, was an absolutely gripping, uncomfortable listen. Similarly, the Greenham Common episode earlier this month was riveting, both for the retrospective glimpse behind the scenes and a sense of how little the positions of those gathered together had changed. The three women retained steely conviction about their actions, while the establishment – represented by a former RAF base commander and a former Conservative local councillor – still didn't quite know what to do with them. The councillor tried some patronising taunts ("We are not interrupting, it is the ladies each time"); you really hoped and trusted MacGregor glared at the word "ladies". As well as the gulf between guests, the programme benefited from the usual skilful production by independents Whistledown: weaving the story around studio discussion and blending archive news footage and music of the time with MacGregor's crisp narration. The programme intelligently, classily brings the stories of our time to life, but magically tilts the axis towards the individual, personal experience of them from a rich range of perspectives. It's this unique mix that makes The Reunion such impressive, must-listen radio. The guardian .