Bellowhead – or around half the acclaimed, award-winning 11-strong folk band – are huddled under a little marquee by the Thames in front of London's Southbank Centre, where they have recently been inducted as artists in residence. They're surrounded by a large crowd, a good few of whom are sitting at the front with fiddles, accordions, oboes, whistles, even a euphonium. "We put songs up on the website," says the band's lead vocalist, Jon Boden, "so people could come and play along. It's all traditional English dance music – not stuff we do normally. It was busking it, really."
"At times, we stopped and listened to them play," adds Andy Mellon, the band's trumpeter. "And they really sounded good." Bellowhead were guests at the centre's festivities last winter following the reopening of the Royal Festival Hall in June 2007, and the band are preparing ideas for their Southbank residency that begins next spring. Morris dancing for Olympic athletes is one. Another is to dig an allotment up on the Festival Hall's roof. "There's a beehive up there already," says Mellon. "Maybe we'll put a greenhouse at the top."
The Brighton Morris troupe perform in full regalia between Bellowhead's two sets – it's enough to make the police boat idling on the river swing by for a closer look. Morris was forbidden under Cromwell, but the Brighton Morris Men draw an attentive crowd. You wonder if this kind of hardcore English fringe culture is in the process of coming home to itself.
Whether or not there's a Morris revival on the horizon, there are dozens of young artists revitalising the tradition, and English folk is in ruddy health, sprawling from the indie acoustica of Noah and the Whale via the likes of Seth Lakeman and Jim Moray, and to bands such as Bellowhead, whose repertoire encompasses not only the tradition but the contemporary – pop, world music, 20th-century classical and jazz. It's a powerful mix that won them a BBC Radio 2 Folk Award this year (for the third time) for Best Live Act.
"Initially, what we wanted to be was an English folk music party band to finish off festivals with," says Boden, who also has a acclaimed duo with fellow Bellowheader Jon Spiers."To be a headliner at big festivals and have everyone jump up and down to us. We've adapted that, but it's still our aim at every gig to get everyone dancing."
Bellowhead are from Edinburgh, Newcastle, Oxfordshire, London, and the South-west. Together, they embody the riotous power of traditional English songs played acoustically, but in a contemporary way.
"We're not a period piece band," affirms fiddle-player Paul Sartin. "To be a party band, the music has to be accessible, and therefore contemporary. We haven't deliberately set out to update folk, but because we bring so many influences into the band – jazz, pop, other folk traditions – it gives it that air of experimentalism. We use the songs as a template, chuck everything into the mix and see what comes out."
The band are start touring their new album, Matachin, this week. It's a dark and riotous collection that ranges from a Scott Walker-ish version of the ghoulish "Spectre Review" to singer Boden's arrangement of a classic "night visiting" song, "I Drew My Ship Across the Harbour" (about a ghost coming back to haunt his lover), and the inexorable moral descent that is the "Widow's Curse", taken from a lengthy 18th-century broadside on "the lewd life of a merchant's son of London and the misery that at the last he sustained by his riotousness."
"We have a fairly free approach to choosing material," says chief arranger Pete Flood, who's got a Steptoe's yard of percussion to play with in his drummer's seat behind the band. "We might choose a piece from the tradition and cast around to see what we can juxtapose it with, what in the present day works well." "Spectre Review", taken from an old German folk song about a ghostly regiment of soldiers on parade, is a case in point. "Jon [Boden] brought in 'Spectre Review' and I wanted to do what they did for Scott Walker's album of Jacques Brel covers," says Flood, "something very dramatic, dynamic, orchestral, And it was the perfect thing to go with that idea."
Elsewhere, Kipling's barrack-room ballad "Cholera Camp" is set against a backwash of barbershop vocals, and snatches of Shostakovich and modernist dissonance disrupt the Jacobean mores of "Widow's Curse". The album's title comes from the links between Morris and the matachin sword dance, which had its roots in renaissance Europe before travelling to Latin America. "It's interesting that something perceived as so English is an international folk tradition – though it's very true that all branches of the folk tradition are international," says Boden. "The term Morris itself comes from Moorish, though it doesn't mean the dance comes from there," he points out. "The current feeling is that it comes from courtly dance."
Another very English form that reveals complex roots is the shanty, two of which – "Whiskey Is the Life of Man" and "Roll Her Down the Bay", which they get the South Bank crowds to sing along to – are among the album's highlights.
"The call and response in shanties is African American," says Flood. "There's nothing like it in our tradition." Boden describes them as "English world music – the original world music. They're rhythmical songs with a very simple structure and they're pretty international – ships had international crews and they were passed from ship to ship. They have a lot of syncopation and an African impulse in them. And because they're functional work songs, you can batter them about. With ballads, you can only push them so far, but shanties don't seem to care what you do to them."
Though the last professional shanty singer only died in 1950, the heyday of the shanty man was the 1750s to the 1850s, before the industrialisation of the ports and the arrival of steam. "The number of African-American people employed in shipping fell dramatically from the 1850s," points out Sartin. "There was a big influx of European sailors and a gradual whitening of the crew. But shanty was the first Afro-European mix, and it's very important to our music culture – it appears everywhere, in that it has a central leader that it revolves around."
To match the broadness of their repertoire, which can reel in classical, jazz, cabaret, even music hall into one number, Bellowhead's recording methods have become increasingly open-ended. "With the first album we were tied to the dots," says Sartin, "but for Matachin there's lots of improvisation among the passages we've written in. As we've got to know each other as musicians, we've worked out what other people can do, what their strengths are, and we write to that. If one person does an arrangement we'll take it to the others and ask, what do you think?"
"Even when it is arranged, it's open to be Bellowheaded," Mellon adds. "It's a template. People bring their sound to it, regardless of what you've written – in a good way."
"The ideal," continues Flood, "is to come up with something where you can't tell which is which." To achieve this, the band rehearsed the album in a barn before going in to lay down the brass, percussion, squeezebox and guitar live in the studio, adding the strings later.
Spending a few hours with four of Bellowhead's 11, you can see how their energy, intelligence and sense of purpose has forged what is fast becoming one of folk's most successful big touring bands. They're working in the tradition, but they're far from being purists. "It's about working in folk and doing something experimental that has pop sensibilities at the same time," says Flood. "Like what Brian Wilson did with The Beach Boys, or Wilco with Jim O'Rourke. Something to mix those two, which doesn't often happen. It's what makes albums like [Van Morrison's] Astral Weeks or [Brian Wilson's] Smile – all the albums that people think extraordinary. If we could do that in a folk setting, that would make my life complete."
Bellowhead is touring the UK from Thursday to 1 February ( www.bellowhead.co.uk ); 'Matachin' is out now on Navigator