Sex + teenagers = 1FM

It's Often cold in January. You can get sick of turkey. Teenagers tend to be messy. These are self-evident truths that need no telling, save a sigh as you stamp snow off your boots, or hurl a carcass to the wolves, or bend to harvest the trail of grimy mugs, tangled tights and crumpled horoscopes that chart your little treasures' progress through their environment. Yet, on Sunday, R1 decided to boldly go right into the Secret Bedrooms of its audience, even commissioning a Mori poll to peer under 407 duvets and climb on to 407 wardrobes in the interests of serious research.

Some listeners, warned Mary Ann Hobbs, might find the teenagers' frank revelations uncomfortable. This was a strange remark as, surely, most listeners were the peers of the polled, who would be enormously comforted to have it confirmed that other people, too, smoke out of their windows, play loud music and bicker with their parents. Perhaps she meant sex: such warnings often do. Yet here the evidence was confusing. Fourteen per cent, we learnt, claim an average record of once a week; a moment later, this statistic was described as two out of 10, betraying either a lack of familiarity with basic maths, or an ambitious, febrile imagination. Come to think of it, either of those might well cause adolescent discomfort.

The figures - and the bedrooms - became even less comfortable when we reached electrical equipment. Everyone (honestly, Mum) has a stereo, television, video, computer and telephone in among the posters of Pamela Anderson or Brad Pitt, the rotting tangerines, the shampoo bottles full of drink, the incense, gargoyles and mirrors cluttering their rooms. Yet, thank goodness, the girls still love to gossip and write letters, and one of the boys - possibly the one who confessed that he was "still pure" - spent hours the other night watching the stars with his friend Stacey.

Perhaps he'll grow up to be a cosmologist. There was one ready to Start the Week (R4), or end the year, or begin the universe this week. Sorry, correction, universes. Martin Rees thinks that ours is one of an ensemble of universes, all beginning with separate big bangs. We'll only grasp this when we fully understand the extreme physics of the first micro-second of time. In my case, that could be never, if never is a concept available to cosmologists. Melvyn Bragg knew just what he was doing when he unleashed this man on an innocent world. Tell people your theory, he said, and you'll really finish them off.

It was a vintage session. Brenda Maddox was all relaxed intelligence, Lewis Wolpert assertive arrogance ("I happen to be right"), and Jude Kelly fiery asperity. God put in an appearance after 37 minutes, some considerable time after the first micro-second. He didn't stay long.

Its sister programme, Midweek (R4), starred a gorgeous man. Billy Ivory wrote the TV series Common as Muck from experience. He spent three years on a dustcart and his stories were hilarious. He didn't mind the smells - though other people, like shopkeepers, did - but he bewailed the invention of the disposable nappy, with its tendency to parachute on to the left shoulder. They always got their Christmas boxes on his cart. They'd start singing carols about September, and woe didn't half betide anyone who failed to respond.

The career dustmen called him "youth" when he was heaving bins, which leads us back to teenagers and a strange archive programme about The Beatles at the BBC (R2). Alan Freeman introduced tapes of himself talking to the boys 30 years ago, when young people were treated to half-an-hour's pop music a day in a programme called Teenagers' Turn. Much was made of the fact that 17 previously unreleased recordings would be heard, but they were pretty dreadful covers, mostly. Thirty years ago, Rolf Harris sounded, eerily, exactly the same, but Freeman himself used to be much, much posher. There was a chap who clearly despised them called Lee Peters: they called him Pee Litres. Who could have imagined, then, that all this was going towards the creation of Sir Paul McCartney?

Some 40 years before the Beatles made their famous tour to Hamburg, a group of young black musicians arrived there. Amazingly, one of them is still alive, still playing and still chuckling about those days. Doc Cheatham is 92 now, but he remembers every detail of his sessions with - you can scarcely believe the name - The Chocolate Kiddies (R4).

Of course they travelled there by boat, and Cheatham used the trip to learn German: he was fluent when they arrived. German music was all oom- pah before their appearance, but they made it swing. Kurt Weill was inspired by them and the whole Christopher Isherwood/Cabaret milieu grew out of their tour. Peter Staveacre's programme was a fascinating glimpse through a sparkling window which was, all too soon, to be slammed shut by the Nazis.

Finally, New Year's resolutions. Sue Nelson was Born to Be Perfect (R4), but her choc-holism has blurred the outline. On Thursday morning, she set out to regain her physical splendour, bearing in mind that razor- sharp cheekbones are the best fashion accessories. She failed, heroically.

There were lots of suggestions, but she resisted exercise, shallow breathing and lymphatic drainage - also colonic irrigation, despite its Royal seal of approval. A telephone session with a psychiatrist offered three solutions: a brisk walk, eating an apple or cue-exposure. She said the only walk she'd take was to a sweet-shop, but she didn't need to as she had a handy bar of chocolate with her. Open it, he said, study it and then, firmly, throw it ... Too late. It went straight into her mouth.