As a kid I had a train set. My favourite thing about it wasn’t the tracks or the engines, but the buildings, made by a company called Superquick, that went around the edge. One of these was a cinema, and the film showing, that week and every week, was called The Music Man. The name was so generic I assumed it was made up. Then, when I was about eight or nine years old, I was given my first album, a hand-me-down copy of With the Beatles, and I discovered – thanks to Tony Barrow’s sleevenote – that Paul’s lilting ‘Till There Was You’ was from a film called The Music Man. Barrow explained that it had also been recorded by Peggy Lee, whom I thought of as a grown-up singer – nothing to do with the Beatles or the glam rock acts dominating the radio. What was The Music Man? I guessed (rightly) it was a musical. Who starred in it? Who wrote ‘Till There Was You’? How did the Beatles end up covering it? I assumed someone would tell me more about it when I grew up, but no one did. The moment had passed. The Music Man was a forgotten moment from my parents’ youth, and if it wasn’t for my Superquick cinema – freezing time in 1962 – I may never have come across it.

When I was writing Yeah Yeah Yeah: The Story of Modern Pop, I was constantly aware that pop music didn’t begin with the Beatles in 1963, or Elvis in 1956, or even with the first seven-inch singles in 1949. There was a prehistory that went right back to the first recorded music, at the turn of the twentieth century, and that a tangled web of new musical forms – mostly American – had led to shows and films like The Music Man. What’s more, the chronology confused me. I had clots of knowledge about the Great American Songbook writers, and New Orleans, and blues, and early Hollywood musicals. I had read exemplary books on individual genres, but they rarely mentioned the myriad other contemporaneous pop forms. So much tended to be slung into an all-purpose folder labelled ‘old-time music’. I realised that no book described what popular music had sounded or felt like – or even explained what was truly popular, and when – before rock ’n’ roll.

To that end, Let’s Do It is a guide through the pop music of the first half of the twentieth century, unravelling all the genres, styles and names that can seem tangled to the casual fan of George Gershwin, Billie Holiday or Rodgers and Hammerstein, and finding the silver threads and golden needles that bind them all together.

What makes pop music exactly? For me, its essence is the record itself – the grooves, the label, the feeling of permanence. The act of listening to something more than once, of playing a record again and again, separates ‘pop’ from the merely ‘popular’. The advent of records affected the way music was written, played and performed: if a 78 rpm disc could only handle three minutes of music, then a song couldn’t be more than three minutes long. 1900 is the sweet spot, when a brand-new musical form – ragtime – linked arms with the nascent pop music industry and launched the twentieth century. And that is where this story begins.

In 1900 recording technology was still so primitive that acts had to play as loudly as possible in the studio, gathered around a giant horn. The story weaves through the fall of British pop influence during World War I, the rise of the American Jazz Age in the 1920s, the sound of swing, and the triumphs of Broadway and Hollywood musicals in the ’30s and ’40s. Post-war, pop’s forward motion faltered. We will discover an era that created some extraordinary music but lacked direction; when the Songbook writers were in decline and jazz splintered; when Frank Sinatra made his hippest and best albums, but with songs that were mostly decades old. Rock ’n’ roll moves into this vacuum in the ’50s, and the Beatles presage an unlikely swing of the compass from New York back to London in the ’60s. The story concludes with the beginnings of a rapprochement between the old pop world and the new age of rock and soul in the ’70s. As it turned out, and with the benefit of twenty-first-century hindsight, they really weren’t so cosmically different.

Pop music developed, in almost every genre, every style, thanks to a constant push and pull. For every cheeky Lionel Bart, gamely making light of the Blitz, there was a prim Ivor Novello hankering for the cucumber sandwiches of his turn-of-the-century childhood. There was the maximal rhythm of Count Basie and the minimal softness of Claude Thornhill; the furrowed Jerome Kern and the flighty P. G. Wodehouse; the bellow of Sophie Tucker and the squeak of Helen Kane; the Andes siren sound of Yma Sumac and the lounge-bound purr of Julie London; the rough Louis and the smooth Hutch. Music could be hot or it could be cool, and that didn’t apply only to jazz. This was an age when mass media and pop culture were struggling to establish themselves. Multiple strands were all fighting their own corner: radio and jukeboxes did not work hand in glove; musical theatre looked down on Hollywood; Chicago mistrusted New York; Britain feared Americanisation. Binaries and dichotomies emerge throughout the story – trends and splits, the ebb and flow of the progressive and the conservative, the interplay of different classes, different cultures.

Let’s Do It is about records that were made to sell, music that was intended to be heard by the largest possible audience, whether performed in travelling vaudeville shows, on West End and Broadway stages, on celluloid printed in Hollywood and Shepperton, or on 78, 33 and 45 rpm records. It is an Anglo-American story, with early nods to sounds and styles from Vienna, although outside influences are constantly absorbed and co-opted from around the globe – Hawaii, Cuba, Brazil – essentially as land-grabs.

We’ll discover how calamities shaped the future. The baritone Jacob Schmidt was caught in a mustard gas attack in World War I, which permanently affected his voice; he re-emerged in the 1920s as Whispering Jack Smith, with his hit song ‘Me and My Shadow’. His voice was so soft it was inaudible on stage, but it was perfect for the intimate new world of radio – the crooner was created. During World War II, the Germans used their newly invented tape recordings to give the impression that Hitler was in eight places at the same time. The technology was brought home by victorious American soldiers and adapted so that Bing Crosby could play golf while his radio show was supposedly being broadcast live. We’ll see how World War II broke up the swing bands, putting the post-war focus on solo singers like Frank Sinatra and Peggy Lee, and how Tin Pan Alley’s infantilism in the 1950s left the door open for the music of the underclasses – rhythm and blues, country and western – to win back the youth crowd with the schism of rock ’n’ roll.

I love pop music that delights in trespassing formal boundaries, but I like it even more when the trespass is accidental. I’m fascinated by how the Great American Songbook, the music of the nation’s second-generation immigrants, was a construct that its creators only pieced together once its commercial hold began to slip in the 1950s. I love it when a ‘fake’ form does something that the ‘real’ or ‘proper’ original has failed to, whether it’s Irving Berlin interpolating ragtime at the wrong speed in a New York bar, or Little Walter playing blues with a distorted, amplified mouth organ, or Gene Autry singing cowboy ballads with a Swiss yodel thrown in. Or George Gershwin’s ‘Rhapsody in Blue’, which in 1923 aimed for the ‘serious’ but also showed how pop could head towards new emotions, cleverness and fun; it suggested the sense of something quite different arriving, a possible future that was free of borders and discrimination.

An unavoidable fact throughout Let’s Do It’s narrative, though, is that from the 1870s to the mid-1960s – almost the entire timespan of this book – segregation was legally in place in many American states, and for most of this time Jim Crow racism wasn’t ebbing away but intensifying. As well as jazz and blues, minstrelsy always lurks in the background of America’s pop energy. So, along with the creative triumphs of Louis Armstrong and Nat King Cole, there will be some horror stories.

Another thing to be borne in mind is that women having any kind of career – let alone one in the music industry – was far less common in the first half of the twentieth century than it would become in the second. The upshot of this is that hardly any women had pop careers that spanned decades, so it feels good to have the chance to acknowledge under-appreciated female talents, like the pioneering crooner Vaughn De Leath and the bandleader Ina Ray Hutton, as well as more familiar stars such as Sophie Tucker, Peggy Lee and Barbra Streisand, who did overcome the odds to enjoy long-lived success. Delving into the stories behind the familiar and unfamiliar names, we see how both the music and the lyrics tell the story of race, class and emancipation...