THIS is a public warning: if you’re averse to accordions, fear fiddles, and are hostile to harmonicas – stay well away from Oxford next month.

From April 16-18, the streets, squares and ale houses of the city centre will be transformed into a seething riot of sticks, bells, and tankards – all to a soundtrack of wheezing squeeze boxes, sawing fiddles and frantically strummed guitars.

Yes, it’s Oxford Folk Festival – and this year it’s bigger than ever.

The three-day extravaganza features a packed programme of sessions, workshops, dances, displays and gigs – headlined by avant-folk band Bellowhead, Irish singer Cara Dillon and the quite bizarre Warsaw Village Band.

And, with live street music, massed Morris dancing, and a procession through the centre, no-one will be able to avoid it.

“I’m very excited,” says festival director Tim Healey.

“We have a fantastic line-up – and we’ll be flooding the city with music and dance.”

Now in its seventh year, what started life as a select gathering of roots aficionados has been transformed into one of the liveliest weekends of the year.

“It will be wonderfully colourful, with something for everyone,” says Tim. “We will have sets by all sorts of artists from young cutting-edge acts to some very well-established names.

“There are also hands-on workshops and ceilidhs, and music everywhere – from Oxford Castle, where hundreds of Morris dancers will be performing, to Cornmarket, which will see an extraordinarily vibrant parade.”

The appearance by folk superstars Bellowhead is causing particular excitement.

The 11-piece collective, brought together by squeezebox player John Spiers and guitarist/fiddler Jon Boden, won this year’s BBC Folk Award for Best Live Band and are a dizzying theatrical spectacle – combining elements of Victorian music hall and burlesque.

And, along with folk heroine June Tabor, Spiers and Boden have agreed to take on the role of festival patrons.

“We are especially thrilled to have Bellowhead back – because we actually gave the band their first gig in our first year.

“Our fates are intertwined.”

“Oxfordshire has an exceptional folk tradition,” he goes on. “It has produced acts like Spiers and Boden but also many younger acts like Megan Henwood, from Henley, who is amazing. And we will show off some of the best acts on the local scene.”

Tim gets involved himself, with his band The Oxford Waits, who perform historic ballads, airs and dance tunes in 17th century costume.

And anyone who thinks folk music is only for bearded tankard-wielding blokes and earnest women in woolly jumpers and sensible shoes, has a surprise in store.

“There’s a huge revival in folk music,” explains Tim. “A lot of hip young guys are getting into Morris dancing and there’s a lot of young blood in the music scene.

“Folk is attracting people who are bored of the homogenised pop and rock scene, because it’s rootsy and it’s real.”

John Spiers, whose dad Stan is a squeezebox virtuoso, himself, and an heroic figure on the county’s Morris dancing scene, is typical of the new breed of folksters. “If you hear us you’ll have a good time,” he explains. “Just don’t expect us to sound like folk!

“The tunes may be traditional and the music has come down the years, but we have got hold of it and play the tunes in a way which suits the lyrics – but not in a traditional way. We have a very high-energy set, especially at festivals, where we really do play hammer and tongs!”