One hundred years ago this summer, from high above Daventry in Northamptonshire, voices began to beam into the homes of 20 million people. They came from the 500ft tall Borough Hill transmitter – truly revolutionary technology in 1925 – which opened with a new work, Daventry Calling, by the poet Alfred Noyes.

“Sitting around your hearth/Ye are at one with all on earth,” the poem concluded, giving a utopian flavour that recurs often through Beaty Rubens’s meticulously detailed, engaging book. Exploring how radio transformed the lives of Britons between the two world wars, it’s a striking read in our smartphone-dominated world, as we witness another radical invention quickly becoming part of everyday life. A portal into other places from your own house was also an easy concept to sell. Take the cover of the first Christmas issue of Radio Times from 1923, one of many fascinating images in the book, showing a rapt family gathering around their small set.

Rubens, a BBC producer for more than 35 years, is keen for her book to show how radio affected people’s lives – “the shift in household habits, the awakenings of new tastes, the alterations and adaptations of attitudes”. Evidence for this was minimal before she discovered the work of two pioneering audience researchers, Hilda Jennings and Winifred Gill, whose 1938 explorations into radio’s effects on working-class people in Barton Hill, near Bristol, was published, and quickly overlooked, in the week Britain declared war on Germany.

In a box in the Bodleian Library, Rubens found the pamphlet and Gill’s original notepads, full of rare examples of early feedback. These included radio’s effects on a man who was once drunk and abusive (“his wife used to tremble when he came home at night, but now he never goes out on Saturday nights even… he used to keep pigeons, now he breeds canaries”), a Welsh grocer obsessed with the news (“I’ve even neglected the bacon machine”) and a husband who tunes the radio to foreign-language stations when he leaves for work, so his wife can’t understand it, then disconnects it completely when he goes away for a conference. “She’s left him now,” trills the interviewee on this subject.

Rubens’s findings may have been the book’s impetus, but other stories around the development of radio put flesh on these bones. We learn about a forerunner, the 19th-century Electrophone, which played performances and shows over phone lines (in a gorgeous piece for the Strand magazine, children’s writer Arthur Mee calls it the “pleasure telephone”). We’re also told about wireless communications more broadly: they may have saved some lives on the Titanic via an SOS call, but they also hampered them (richer passengers on board were invited to send wireless communications back to shore, which jammed the channels, meaning several ice warnings were missed).

Fabulous characters crop up too, such as Nellie Melba, the Australian opera singer who gave the first live broadcast performance in 1920. She initially declined the invitation in a diva-like fashion (“my voice is not a subject for experimentation”) before, Rubens notes, she was offered “£1,000 (about £45,000 today) which, even by her standards, must have seemed easy money for a 20-minute recital”.

The book’s most moving moments offer radio as a lifeline. A Mrs Ettery reported that there was now “much more to talk about… there are so many interesting things on the wireless”. What a joy, too, to read about director general Lord Reith’s first director of talks, Hilda Matheson, who informed the BBC’s style (“she was passionately committed to the novel idea that broadcaster should not speak at listeners but make them feel that they were in the room together”). She also launched weekly discussions with female MPs and a show called Questions for Women Voters in 1928. A year later, 10 more women MPs were elected, raising the number to 14.

The finest testimony, however, comes from a 1928 letter to the BBC from a “clerk in a provincial city”. His life is “a tram-ride to the office, lunch in a tea-shop or saloon bar, a tram-ride home” and he can’t spend much money, “because you’ve got your holidays to think of”. But, he adds: “Please don’t think I’m complaining. I’m only writing to say how much wireless means to me and thousands of the same sort. It’s a real magic carpet.” Almost 100 years later, despite our world being so very different to his, radio, at its best, continues to be.