In this episode we welcome the left's very own "national treasure" Billy Bragg – beamed in from his adopted Dorset – and ask him about the long and remarkable career that's enshrined in forthcoming box set The Roaring Forty.

Billy revisits his Barking boyhood and early pop and folk influences, culminating in the 1977 formation of Clash-inspired punks Riff Raff. After a brief 1981 detour via the British Army, he explains how he settled on his unique solo style and delivery – and how he wound up on the cover of the NME in January 1984.

Inevitably the conversation turns to politics and the way Billy has managed to retain his charm, humour and compassion in the face of hatred and extremism. An audio clip of Spectator editor Boris Johnson haranguing him at Glastonbury in 2000 is followed by discussion of left-wing patriotism, Jeremy Corbyn's Labour Party and our present-day hyperpolarisation.

Martin recalls the day Billy came to tea to ask about the RBP co-founder's father Bill and uncle Ken – and the catalytic impact Ken Colyer's Jazzmen had on the music Billy chronicled so impressively in his 2017 book Roots, Radicals and Rockers: How Skiffle Changed the World. From the Colyers and Lonnie Donegan we cross the big pond to talk about Woody Guthrie, the agit-folk bard whose lyrics Billy and Wilco turned into 1998's Mermaid Avenue album. Clips from Chris Smith's 1999 audio interview with Woody's daughter (and archivist) Nora Guthrie prompt conversation about the Okie icon's mighty legacy.

After Mark quotes from recently-added articles about the Stooges, Frankie Goes to Hollywood and Dr. Dre, Jasper wraps matters up with remarks on Truth Hurts and FKA Twigs.

Many thanks to special guest Billy Bragg. For more about The Roaring Forty, as well as Roots, Radicals and Rockers, visit his website at billybragg.co.uk.

Pieces discussed: Billy Bragg on the cover of the NME, Who the hell does Billy Bragg think he is?, Billy Bragg comes to tea, Nora Guthrie audio, Billy Bragg's Mermaid Avenue, The Stooges, Frankie Goes to Hollywood, Dr. Dre, Truth Hurts and FKA Twigs.