The Week In Radio: It's great that Feltz has answered the call from Radio 2

It's a fine art, presenting a phone-in. Like politicians, presenters face the daunting occupational hazard of having actual contact with the public, however chatty, deranged or boring they may be. It was Peter Cook who first realised that you could call in and say just about anything you liked, live on air, as long as you weren't obviously obscene. He spent many happy evenings between 1988 and 1992 calling Clive Bull's late-night LBC phone-in, posing as Sven from Swiss Cottage, a bipolar Norwegian fisherman engaged in a fruitless search for his estranged wife and talking about fish. You can still hear some of these meanderings on YouTube. "You sound a bit depressed," says Clive, unnecessarily.

It would be hard to imagine Vanessa Feltz tolerating depressed Norwegians. Her manner is brisk and non-patronising. Unlike some hosts over at rival commercial station LBC, she does not court outrage, or insult the intelligence. Inevitably, being a morning presenter on BBC London means that she has to focus on "the stories that matter to the capital", ie roadworks – "41,078 permits issued since January to dig up our roads!" But Feltz's world is about to expand dramatically beyond traffic cones when in January she takes over the Radio 2 early morning show vacated by Sarah Kennedy, who vanished without warning in August.

"I'm not going anywhere. I'm just going to be presenting the baby breakfast show as well, plus my afternoon job at Greggs and a paper round," she assured Radio London listeners cheerily, before kicking off a debate on immigration.

But while this is a great and timely move for Feltz, the big question is, can she do cosy? Bob Shennan, Radio 2's controller, might call her "the ideal companion to our millions of early-bird listeners", but those struggling awake in the very earliest hours require very gentle handling. Kennedy's audience, who called themselves the "dawn patrollers", enjoyed an eccentric world of nicknames and whimsy. They loved Kennedy, who referred to herself as Bunty Bagshawe and had five cats, and defended her when she was targeted for slurring words and suffered jibes about alleged drinking. What will they make of Cambridge-educated Vanessa, who is crisp and uses words like "solecism"? It's impossible to imagine Feltz adopting a silly nickname or sympathising with Kennedy's story that she nearly ran over a black man until he opened his mouth – a remark for which she was rebuked. If anything, Feltz would seem more at home on Radio 4. Her Monday debate topic, "Is it time to put grammar back on the map?" is the closest subject to Radio 4 hearts. The other question is how soon doing both shows, and deputising for Jeremy Vine, will tire her out. My hunch, though, is that Feltz will go far, Radio 2 is lucky to have her and she is a welcome female complement to the impressively intelligent line-up of Simon Mayo and Jeremy Vine.

Today, you might discuss your problems on a phone-in, but 100 years ago they did things differently. In 1910 Gustav Mahler, finding his wife having an affair with Walter Gropius, took a four-hour walk around Leiden with Sigmund Freud. Radio 3's Walking with Freud was an inspired cross-disciplinary chat between composer David Matthews and the psychoanalyst Anthony Cantle. Poor Alma Mahler came off worst. She might have called her husband a psychopath, but Cantle said it was her who was "almost impossible" to live with. "She had a palpable narcissism and was histrionic in the extreme." The Mahler marriage meltdown made for a gripping listen. Back then, the details were tucked away in memoirs, but today, one fears it would be all over the gossip mags. Both sides would do books. You might even find people discussing it in a late night LBC phone-in.