Australia's first radio station began 100 years ago as 2SB, now known as ABC Radio Sydney

It's 8pm on November 23, 1923. A button is pushed, the red light comes on, and radio begins in Australia. 

Radio station 2SB is on the air and, on that first night, a few hundred listeners tune in to hear some "light orchestral" music.

Over the next 100 years, the station, which was renamed to 2BL, then 702, and now ABC Radio Sydney, would transform its programming from serious "talks", bible readings, and unidentified presenters to today's more dynamic style that puts listeners at the heart of the conversation.

Long-time presenter Richard Glover describes modern radio as a "town square".

"On a good day you'll hear someone who's older than you, you'll hear someone younger than you, you'll hear someone who's a different gender to you, you'll listen to somebody who has got different politics to you," he said.

As ABC Radio Sydney celebrates the 100th anniversary of Australia's first radio station, we look back at key moments in its history.

Lectures, mystery voices

One of the performers in the concert on opening night was George Saunders, a World War I veteran and popular singer who became Sydney's first radio celebrity.

But presenters mostly took a back seat in those early broadcasts, which were packed with talks, often delivered by university professors on subjects ranging from "Egypt in retrospect" to "what can be done to beat the bushfire menace".

There were plays, serials, and music.

On Sundays, there were religious services, bible readings, and non-denominational homilies.

At one point, presenters were not even allowed to introduce themselves.

Charles Moses, who would become general manager, suggested listeners could write in if they wanted to know who was on air.

Interviews were non-existent until they were accidentally pioneered by presenter Goodie Reeve on 2FC (which later became Radio National) in the 1930s, when a visiting actor froze during a talk and had to be encouraged to speak.

A marathon broadcast

Even in the early days, the station was keen to get out onto Sydney streets and conduct outside broadcasts, or "actualities" as they were called.

In March 1932 — just a few months before 2BL would become an ABC station — there was a live broadcast from one of the most important events in the history of Sydney: the opening of the Harbour Bridge.

Conrad Charlton — an actor, singer, and broadcaster — was on the scene to report live from 5:30am until 10:30pm.

Many years later he recalled the controversial events of the day.

"The guard was drawn up and the premier was about to declare the bridge open and cut the magnificent ribbon when an individual dashed through the mounted guard and beat the premier to it," Charlton said.

"What a debacle.

In the weeks following, the ABC was inundated with letters in response to the broadcast with many "delighted with the announcer's adjectives".

A lighter tone emerges

For nearly 40 years listeners tuning in to 2BL were more likely to hear politicians droning on than they were to hear presenters or music.

In the 1940s it became mandatory to broadcast federal parliament live.

While popular at first, as the hours of parliament extended, listeners switched off.

It's no surprise that the modern success of 2BL really began when parliament was moved to a dedicated network, which is known these days as News Radio.

The years of broadcasting parliament had a lasting influence on the station's identity.

Prior to 1961, 2BL had been the serious station and 2FC had been the home of light entertainment.

But due to the preponderance of parliament, 2BL mostly dispensed with its serious talks, dramas, and news programs.

Instead, it used music and light entertainment to fill the hours between the sittings of parliament.

So 2FC became the home of serious programs, and 2BL became lighter in its approach.

The fierce rivalry between 2BL and 2FC (later Radio National) led to sometimes bizarre stunts designed to attract listeners, such as broadcasting from down a coal mine in Balmain, onboard an aircraft with the pilot singing along to gramophone records, and from the bottom of Sydney Harbour with two divers.

As the 60s went on, more specialist shows — often about music — emerged.

'Bonsai' cannabis chat

The ABC was late to embrace talkback due to the unpredictability of the form.

When it did take its first tentative steps into talkback in 1973, about five years after commercial radio, callers were invited to discuss what was predicted to be a safe subject: gardening.

But as then-presenter Allan Humphries explains, it didn't exactly work out that way.

On the third gardening program, a man rang in asking if it were possible to "bonsai" marijuana plants.

"He said, 'I've got these marijuana plants in the back garden and they're getting a bit tall and I'm afraid the police are going to spot them','" Humphries recalled earlier this year.

Despite the rocky start, once the lines were open, there was no turning back; callers' opinions and stories became key to bringing a subject to life on air.

'Just a stupid idea'

But not all presenters embraced talkback.

John Doyle was Afternoons presenter in the late 1980s and early 1990s and considered talkback "an excuse for a better idea".

"For those who sit around all day … coming up with topics you're going to run with that day … 'Which sock do you put on first? Left or right? Give us a call' — well, to me this was just a stupid idea, I could never warm to it," he said.

Breakfast presenter James Valentine disagrees.

He loves the interaction with callers, but he's not so much interested in their views on the latest government decisions.

"I started to devise these ways of getting them to tell me stories of their life … like 'what's the worst wedding you've ever been to?' so you collect these fantastic stories on bizarre weddings," Valentine said.

Valentine suspects some might be aspiring actors or improv artists, but he says the key is to have a "gang of about 100 regulars" who will get involved.

Conduit for connections

Through breaking news and in natural disasters such as bushfires and storms, talkback means we can hear from people on the ground directly affected.

In COVID lockdowns and restrictions, talkback radio was a way of connecting to other residents in the city.

One of the best moments in radio for Mornings presenter Sarah Macdonald happened during lockdown when she was broadcasting the Evenings program from home.

A woman named Sandra rang up about her childhood hero, a boy called Wayne who had rescued her after she'd fallen in the playground.

"I said, 'Wayne if you went to this school in this period, can you call us?' and Wayne called and we got them back together," she said.