Billy Bragg, 59, is a musician, author, broadcaster and leftwing activist who fronted the 1980s Red Wedge movement with, among others, Paul Weller. Bragg’s albums include Talking With the Taxman About Poetry, and Shine a Light with Joe Henry. He has helped curate Glastonbury festival’s Left Field stage since 2010. His new book, Roots, Radicals and Rockers: How Skiffle Changed the World, explores the history behind Lonnie Donegan’s 1955 chart breakthrough (with Lead Belly’s Rock Island Line) and relates how skiffle paved the way for the new era of guitar-led music from the likes of the Beatles and the Rolling Stones.
Was the book a labour of love?
It’s something I’ve always been interested in. Most British pop history has been combed over, but skiffle hasn’t really been given the attention it deserves.
Skiffle, featuring washboards as instruments, has almost become a joke, but at the time it was revolutionary…
Back then, no one believed that they could be a pop star. Lonnie Donegan passed on the two most revolutionary ideas ever imparted to British youth – you didn’t have to be a musician and you didn’t have to be American. Van Morrison was 12 at the time and already aware of Rock Island Line, but he would have no more imagined singing songs like that than fly to the moon. As Van Morrison says to me in the book, Donegan opened the door.
You cite the similarities between skiffle and punk – the DIY spirit...
My experience in punk rock was really helpful in understanding how skiffle empowered people. For me, it was seeing the Clash on the  Rock Against Racism tour and realising that my generation was going to define itself in terms of opposition to discrimination of all kinds. On that, I based my theory about how music can help the process of change, though only the audience can make that change. Music itself doesn’t have agency, though it can give you a different perspective and that’s also true of love songs. You can be in the deepest trough of heartbreak and hear Smokey Robinson’s Tracks of My Tears and it’s as though he’s been reading your mail.
Do you resist being portrayed as a leftie‑cartoon character?
No, I’ve made my bed, I’m happy to lie in it. It’s partly my fault for going on Question Time more than Later… With Jools Holland, but I think if you’re offered a platform you should take it. I do think it’s fairer to talk about topical songs rather than political songs. Otherwise, you’ll put off young artists because they think they’ve got to know everything about politics, which isn’t true – they just have to write about the pressure they’re under.
When the London Philharmonic Orchestra performed your new lyrics for Beethoven’s Ode To Joy in 2009, you shook hands with the Queen to please your mum…
When you’re “Billy Bragg”, you’ve got to do things that confound people that pigeonhole you. Shaking hands with the Queen was an opportunity to break down my stereotype.
You support Jeremy Corbyn. If, as predicted, Labour lose, would you vote for Corbyn as leader again?
After the election, we’ll have to see what the situation is, what’s thrown up. I’m hoping that Labour will win, but if they don’t, the shock may be that Theresa May doesn’t get the landslide victory they’ve all been bigging up.
Are you going to tactically vote?
No, I’m a party member now. I’ll be voting Labour. People should make their own decisions about the constituency they’re in.
You complained about being misquoted by the Times at the Edinburgh book festival, saying that Corbyn was a “20th-century man” who couldn’t reach the electorate…
What I was trying to say was that it was the 21st century and it was disappointing that there’s nothing about PR [and devolution] in the Labour manifesto.
Were you disappointed by the Labour whip to trigger article 50 for Brexit?
I was disappointed by the referendum result. Afterwards, I didn’t see what else they could do – the party has to accept the democratic will of the people.
The referendum was advisory…
That should have been written on the side of the battle bus: “Do you want to leave Europe? We’re only asking for advice here, not a command.” It’s a bit late now. “I was only advising you to knock down my house – I wasn’t asking you to knock it down.”
You performed on the Left Field stage just after the referendum result – what was that like?
It was 100,000 people in a field, most of them in a daze, seeking solace, but determined to join together. My son [Jack], who’s seen me play many times, said: “Wow, Dad, I’ve never seen you do that before.” And I said: “Son, that wasn’t me. I wasn’t driving that gig, I was riding it.” That gig had its own momentum and I was trying to steer it as it barrelled along.
You’ve been accused of “champagne socialism”; is this an attempt to embarrass people into not sticking up for others?
The war on empathy, accusations of political correctness, virtue signalling, all that, are attempts to stop two forces coming together – empathy and activism. Put empathy and activism together and you get solidarity, the key driver to social change. As a musician whose currency is empathy, it’s my duty to make people go away feeling that they’re not alone, with their activism recharged, like on that Brexit night at Glastonbury.
What’s your view on President Trump?
I’ve just written a song based on a work by Goya, borrowing the title The Sleep of Reason Produces Monsters. I think that’s where we are at the moment.
You’re turning 60 this year; inside, are you still the young kid who’s fired up from seeing the Clash?
In some ways. I just did Later… for the book, Paul Weller was playing and watching him it was like we were both 19 again. I was so charged to see him – he’s stayed true to what he believes – and it was just really nice. I mentioned to him that we’ve both still got the same haircuts, which for our age isn’t doing too bad.
Would you want to be 18 now?
I’d love to be starting out again – to have it all in front of me.
The dedication is missing from my review copy of Roots, Radicals and Rockers – do you have one yet?
Yes, I’m dedicating it to all the kids who were inspired to pick up a guitar by Lonnie Donegan.
• Roots, Radicals and Rockers: How Skiffle Changed the World by Billy Bragg is published by Faber (£20). To order a copy for £17 go to bookshop.theguardian.com or call 0330 333 6846. Free UK p&p over £10, online orders only. Phone orders min p&p of £1.99