Who would have thought the PM was a folkie?

It came as a shock last weekend to discover that among my fellow punters at a folk concert back in November 2012 was David Cameron. Speaking to the Mail on Sunday, the Prime Minister slyly hinted at the hipness of his musical tastes by revealing how he and Samantha snuck into a First Aid Kit gig as the Shepherd Bush Empire. Until then, I had flattered myself that I had a cool and recherché appreciation of music, and that hopefully I had avoided the pretentious music so often accompanied by the word “recherché”.

The news must also have come as quite a shock to Klara and Johanna Söderberg, the Swedish sisters who form First Aid Kit. As two self-confessed Stockholm lefties, hearing that your number one fan is a dusty Conservative cannot have been the catalyst for air-punching and whooping, though unlike Morrissey they have been too polite to disown him publicly.

While I was never sure exactly what the Cameron austerity mantra “we’re all in this together” meant in real terms, I never imagined that the “this” would be the folk revival led by First Aid Kit, Laura Marling, Ben Howard, Mumford and Sons and others who have taken on the mantle from Ewan MacColl, Bob Dylan and Joni Mitchell.

After decades in the wilderness, the reborn folk music of today in some obvious ways could barely be more different from an ancestry rooted in angry protest about civil rights issues, social injustice and the threat of nuclear war. The scent of woodsmoke from the communal camp fire drifted away from it a long time ago and the lyrics are introspective and confessional. They dwell on the angst and misery that follows failed relationships, rather than the persecution of minorities (Dylan’s “Hurricane”) and environmental destruction (Mitchell’s “Big Yellow Taxi”).

Marling’s ethereal ballads are more philosophical than political, while the Swedish sisters, whose harmonies have won them comparisons to some all-time greats and whose performance of “America” reduced a watching Paul Simon to tears, sing about love and longing. This genre is passionately followed not only by prime ministers, but by a minority of teenagers searching for an “authentic” alternative to the Auto-Tune heavy pop music of Lady Gaga, Miley Cyrus and Rihanna.

Sam Cam has always been a bit on the hippy side, but having to share First Aid Kit with a middle-aged Conservative almost leaves the rancid aura of dad-dancing in its wake.

Ultimately, of course, it could not matter less. The fact that First Aid Kit’s bewitching harmonies are just as resonant to the ears of a 47-year-old Tory as to those of a dopey 16-year-old is a sign of folk’s enduring strength and appeal.

Marling’s philosophical contemplations of desire and loss, most recently cohering in the brilliant album Once I Was an Eagle, could have been released barely unchanged 40, 50 or even 60 years ago. The times they may have a-changed, but the principles of folk music – honesty, simplicity and emotional sincerity – have not.