As it turned out, music’s loss was politics gain. Or more precisely the people of Hull’s, for Johnson went on to spend 20 years as a Labour MP in the city, during which time he served as a cabinet minister in both the Blair and Brown governments, before stepping down last year.
But while he rose from being a postman to Home Secretary and was even touted as a potential Labour Party leader, there is another passion that was an integral part of his life long before he became involved in politics – music.
Johnson grew up in the slums of West London in the late 1950s where he remembers being transported to another world by the dulcet tones of Bing Crosby and Grace Kelly singing True Love – his earliest musical memory.
He was a youngster when rock ‘n’ roll was born and he charts his love of music, everything from Bob Dylan to The Beatles, in his new music memoir – In My Life. He recalls a world of Dansettes and jukeboxes, smoky coffee shops and dingy dance halls, and describes his own dreams of rock stardom, which he does with humour and elan.
The book starts in 1957, when Johnson was seven years old. “There’s nothing that evokes a memory more for me than music and it has been a central theme in my life,” he says. “Us baby boomers went through an extraordinary revolution in music. We went from dance bands and people like Dennis Lotis, to the birth of rock ‘n’ roll, Lonnie Donegan and skiffle and onto The Beatles,” he says.
“In the charts you had things like Pinky and Perky and it went from that to songs like Strawberry Fields in the space of about five years.”
Johnson and his older sister, Linda, shared a passion for music. Their errant father was a pub pianist and music, as he puts it, was in their DNA. “My dad had a piano though he kept it locked. But once he left my sister broke it open with a screwdriver. By that time, though, I’d seen Lonnie Donegan and wanted to play the guitar.”
To many people who grew up in the 50s and 60s, pop and rock music was something new and exciting. “At that time young people were still expected to listen to Vera Lynn. There hadn’t been a generation that had grown up with rock music and suddenly this was the moment when a generation gap opened up through music,” he says.
“I remember my music teacher at primary school seemed to be the first music teacher I’d come across who was interested in pop. She asked the class one day who was number one in the charts and I was the only one who knew it was Poetry in Motion by Johnny Tillotson.”
At secondary school another teacher, Mr Dearlove, introduced him to classical music and the joys of being in the school choir. “When you start to think about how music has affected your life it runs pretty deep. I remember the hymns we used to sing like To Be A Pilgrim, the vocabulary is incredible. Looking at the words was like staring at a rock face you had to climb. You were singing words you’d never spoken before like ‘valiant’ and ‘constancy’. So for me, it was music of all types that went into the mix when I was growing up.”
Johnson says he had an encyclopedic knowledge of who was in the charts as a child. “We used to buy this magazine called Record Songbook that cost thruppence and was printed on paper so cheap you could see the wood coating, but it had the lyrics of A-sides and B-sides.
“I remember the first two singles we bought and all these old ‘78s my dad bought home before he left that we could only look at because we had nothing to play them on until we got the Dansette.”
It’s tempting to see music as a form of escape from the grinding poverty that characterised his childhood years, though such a portrayal is too simplistic. “Music wasn’t something we clung to, to help us through these days, it was just a central part of our lives as it was with kids all over the country.
“You treasured those vinyl records and part of that was because in those days you couldn’t hear songs all the time. There were three radio stations: the Light Programme, Home Service and the Third Programme. If you wanted to listen to classical music you had a whole station dedicated to it, but that was it, there was no local or commercial radio, that’s why the pirate radio stations came along to cater for this huge audience.
“You had to listen to programmes like Housewives’ Choice and Two-Way Family Favourites because that was the only way you might hear a Beatles record. It was nothing like it is today.
“I quote David Bowie in my book when he said ‘soon music will be everywhere’. He said that in the early 70s and now it is, you can access music any time, any place and anywhere. So we’ve gone from famine to feast.”
Many people dream of being a rock star but few make it. However, Johnson actually came tantalisingly close. “For a long time I was convinced I’d make it. I had that audition with Peter Jay and the Jaywalkers who were quite a big band and did these BBC lunchtime music programmes. I was 16 and got shortlisted and I just missed out, even though I thought I looked the part with my candy-striped jacket,” he says, smiling.
Then there was the Area, a band that even got as far as the Regent Sound studio in London, where the Rolling Stones recorded their debut album, and where the likes of The Who, The Kinks and Jimi Hendrix had committed their songs to vinyl.
A big break wasn’t forthcoming and Johnson later joined the In-Betweens, who were talked about as a possible backing band for a Small Faces tour.
However, the fates conspired against him and in the end his music career proved as elusive as the dreams that inspired it.
So does he ever look back and wonder what might have been? “In a way I live my life vicariously through my son, Jamie, who has worked with all kinds of artists. I had that one hour in the Regent Sound studio and I’ve remembered it ever since. Those two or three years of playing on stage with other musicians in front of crowds, the biggest was probably about a thousand at Aylesbury College with the Area, thrilled me so much,” he says.
“Someone asked me recently at a books festival if that was why I went into politics, because I enjoyed the limelight, and there might actually be a bit of truth to that.
“Lots of people of my generation who played in bands are still doing it today and I kind of wish that happened to me, but I got carried into union work and the world of politics.”
And what about that letter and cassette he sent to Elvis Costello all those years ago? “I’m still waiting for a reply,” he says, with a smile.
■ In My Life – A Music Memoir, published by Bantam Press, is out now priced £16.99.
■ The Raworths Harrogate Literature Festival and The Yorkshire Post present a Literary Lunch with Alan Johnson on October 18, at the Crown Hotel, Harrogate at 12pm. Tickets are priced £35. Book online at harrogateinternationalfestivals.com or call 01423 562 303.