By Kevin Young
Entertainment reporter, BBC News
BBC Radio 4 dominates speech broadcasting in the UK, attracting a weekly audience of 9.5 million and more listeners in London than any other radio station.
Can commercial radio, traditionally dominated by music, ever overtake Radio 4, created 40 years ago this week with the rebranding of the Home Service?
When Radio 4 began on 30 September 1967, its schedule contained many shows which continue in 2007.
Today "assumes you are inquisitive and interested", Mr Damazer says
The Today programme was about to enter its second decade, Desert Island Discs was turning 25 and The Archers had been on-air nationwide since 1951.
The man currently in charge of the network, Mark Damazer, says these programmes are "not going anywhere but Radio 4 for a very long period of time".
But he does acknowledge they can never feature in his schedule purely for reasons of nostalgia.
The Today programme has "a more intelligent and questioning approach to its material at that time of day than any equivalent", he says, while Kirsty Young is a "deeply splendid" host of Desert Island Discs.
And he hopes that Grace Archer - one of the original characters in soap The Archers - "would have been pleased" to be "strutting round with an audience of 4.5 million in 2007".
Radio 4 has enjoyed a virtual monopoly on national speech broadcasting for much of its time on-air.
But now, some commercial radio executives see the growth of digital radio - with space for far more stations - as a great opportunity.
Nathalie Schwarz is director of radio at Channel 4, which has been awarded a digital "multiplex" - a cluster of stations - and plans to launch a speech-based service this autumn.
"Radio 4 was part of the whole roots of the BBC. It has an incredible track record and market position.
"However, Channel 4 came into the television market 25 years ago when there were existing players, and found its own place."
Channel 4 Radio will be aimed at those aged 30 to 54, "although it's much more about attitude than segmenting people by age", Ms Schwarz says.
She also promises "a fresh, contemporary alternative to the BBC", including its own morning news programme to rival Today.
"People should be able to enjoy something else that provides in-depth news and current affairs, drama, comedy, documentaries, lifestyle shows.
"We're building on Channel 4's ability to win and retain difficult-to-reach audiences."
The growth of digital radio offers speech stations such as Channel 4 Radio, Sky News Radio, talkSPORT and Oneword "a real opportunity" to dent the BBC's ratings, according to Andrew Harrison, chief executive of The Radio Centre.
Channel 4 insists brands such as Big Brother can work on the radio
His organisation was created last year to champion commercial radio in the UK.
"I think it's never been an option historically because we didn't have a national high-quality frequency to be able to deliver the programming," he explains.
"Speech radio is quite expensive to make - understandably, as you've got a studio full of presenters as opposed to just playing music - so you need to have the national scale to make the economies work."
But Sunday Times radio critic Paul Donovan argues that commercial stations will "never" reverse the BBC's dominance in speech broadcasting.
RADIO 4 FIRST DAY HIGHLIGHTS
0635 Farming Today
0715 On Your Farm
0815 From Our Own Correspondent
0920 A Choice of Paperbacks
0945 In Your Garden
1015 Daily Service
1030 Science Survey
1045 Study Session
1200 Motoring and the Motorist
1310 Round the Horne
1340 Desert Island Discs with guest Roy Castle (pictured)
1415 Afternoon Theatre
1515 Home for the Day
1600 Music at Four
1900 Steptoe and Son
1930 Gala Night at the Opera
2030 Saturday Night Theatre
2310 Music at Night
2345 Shipping Forecast
Source: Radio Times
"Radio 4 costs between £60 million and £70 million a year.
"There's no commercial radio station that is ever going to have a fraction of that."
He plays down Channel 4 Radio's prospects by predicting that "it will be a bit tacky" and "judging by some of the things they've done so far as podcasts, very much the equivalent of Big Brother".
"It'll be brash, young, vulgar, edgy. It won't be a Radio 4 with ads - there's no way it can be that," he believes.
Ms Schwarz insists her company can develop TV programmes as "multi-media propositions", rather than merely rehashing them.
"It can't just be 'TV lite' or spin TV just for the sake of it," she says.
"There has to be a fresh, complementary use for our stations."
Back at Radio 4, Mr Damazer says he "has an idea" of what he would do if he had Ms Schwarz's job - "but I don't, so I'm not going to tell her".
The former deputy director of BBC News is wary of making radical changes, although he concedes he has tried to "mix it up a bit" and "occasionally create a bit of trouble" in his three years as controller.
"I think the great misunderstanding about the Radio 4 audience is that they're resistant to all change. They're not.
"What they don't like is when you suddenly move all the furniture around, in which case they keep on bumping into it and they blame you for it."
Mr Damazer has one other trump card over his rivals - Radio 4 is the designated national broadcaster at a time of a catastrophe such as a nuclear war.
"If something absolutely monstrously huge were to happen, we all end up in a bunker somewhere and Radio 4 will be going.
"In the end, Chris Moyles - even Terry Wogan - will have to cede ground to John Humphrys," he says.
"But I don't look forward to the day," he jokes, "because I think the circumstances would be quite adverse."
Archive audio clips compiled by Pia Harold