If skiffle is remembered at all, it’s usually as a quaint musical novelty – goofy lads belting out makeshift tunes on homemade instruments. Even at the time, the press treated it like a joke.

Skiffle was grassroots. It came from below. It surprised everyone. Billy Bragg

But Bragg believes this do-it-yourself phenomenon was a revolution, not a fad. "Skiffle was a back-to-basics movement that was about the roots of African-American music," he says. He likens it to punk, a low-budget revolt by youngsters tired of more conventional and (supposedly) sophisticated forms of music. "Skiffle was grassroots. It came from below. It surprised everyone."

Bragg came of age in the punk era, and the similarities between punk and skiffle are striking. By the mid-70s, popular music had become big business. Punk harked back to the raw sound of early rock'n'roll, when anyone who knew three chords could form a band.

Likewise, in the early 50s, popular music was dominated by big swing bands and schmaltzy crooners. Skiffle bands rediscovered early blues records, and reinvented them for a new generation. Like punk, skiffle was a reaction against the supergroups and the moneymen. Bragg says: "Skiffle allowed that generation to distance themselves from the culture of their parents. Every generation needs something like that. For me, it was punk."

Skiffle’s most important instrument wasn’t the washboard or the tea chest bass – it was the guitar. In the dance bands of the 1940s, the guitar was a fringe instrument. Skiffle put it centre stage.

The guitar had driven the authentic music of African-American blues singers, music the skiffle bands revered. They also revered trad jazz. "The trad guys believed the real music was only made in New Orleans," says Bragg. "I came away with the sense that British music owes more to New Orleans than it does to any other American city." Liverpool’s Cavern Club, where The Beatles started out, was originally a jazz club.

Above all, skiffle was British. The music originated in America, but it became something else in Britain, where blues and trad jazz came together. Likewise, skiffle was an American word - black slang for a rent party - but as a term for a type of music, it means nothing in the States.