Picture the scene. It's Saturday night and Bestival, the festival season's final fling, is in full, fancy-dress, face-painted, cider-swilling swing. As Doves finish their majestic set and the sun sets over the leafy Isle of Wight country park, Rob da Bank, Bestival's founding father, appears on stage for a brief crowd-rousing DJ set. The opening beats of Faithless' "Insomnia" kick in and... six ballet dancers from the English National Ballet leap and pirouette out on to the main stage. A festival-induced hallucination? Strangely not: this weekend, the troupe's finest classical stars will be bringing ballet to the masses in the fields, dancing to floor-fillers from Basement Jaxx to Michael Jackson, inspired by this year's outer space theme.
The bold union of classical and futuristic has been cooked up by Rob da Bank and Jenna Lee, an athletic young soloist at English National Ballet (ENB). In May last year, the company performed at Bestival's inner-city sibling, Bandstand, an indoor mini-festival at London's Billingsgate Market. Warming up the audience before Mark Ronson's headline set, six dancers performed to an indie mix of Franz Ferdinand and Radiohead, dressed in slinky black leotards, fishnets and punky pink hairpieces. Their offering went down so well, Rob da Bank invited them to Bestival. "People were roaring afterwards. We're never normally on the stage to hear the audience reaction", recalls Lee. "Men were coming up to our boys afterwards, saying, 'I want to learn how to lift a woman like that, that is so cool' ".
The ballet-pop crossover is a growing trend, and it's one that has set traditional balletomanes quivering in their red velvet seats. Michael Clark, ballet's original bad boy, has been doing it for years, dancing to live music from The Fall back in the Eighties. Last week, he celebrated a quarter century of "iconoclassicism" at the Edinburgh International Festival with his new ballet, Come, Been and Gone, set to music by David Bowie, Lou Reed and Iggy Pop and performed by dancers in leather jackets (Bowie's "Heroes"), dresses covered in syringes (The Velvet Underground's "Heroin"), and pointe shoes (Bowie's "The Jean Genie").
When Wayne McGregor became Resident Choreographer at the Royal Ballet in 2006, he set out his stall with an opening number, Chroma, danced to songs by the White Stripes while the St Petersburg-based choreographer Boris Eifman has shocked and amused audiences in almost equal measure with his interjection of Russian thrash-metal interludes into Tchaikovsky's swooping Onegin score.
It doesn't stop there. Martha Wainwright has just followed up her performance in Will Tuckett's Seven Deadly Sins at the Royal Opera House with a collaboration with Christopher Wheeldon's Morphoses company. The new ballet, Tears of Saint Lawrence, with music by Wainwright and choreography by Wheeldon and Edwaard Liang, had its world premiere in New York's Central Park last month. And the Ballet Boyz have been known to play out their shows with a blast of the Arctic Monkeys' "I Bet You Look Good on the Dancefloor".
Pop has been infiltrating austere theatres for a while now, but it's been largely one-way traffic. While the programmers at Covent Garden and Sadler's Wells have slipped the odd contemporary number in among the comforting and familiar on an otherwise classic triple-bill, bringing ballet to gigs and festivals is an altogether trickier proposition. Putting thoroughbred dancers, used to sprung floors and non-slip surfaces, on a stage built for rock stars – strewn with roadies' nails and cables and slick with rainwater – is fraught with danger.
"It's much more nerve-wracking", says Lee, who has never been to a festival before. "At Bestival we'll be able to see the faces in the crowd and they'll be dancing too. It won't be a typical ballet audience at all." Unlike their well-behaved, seat-bound auditorium counterparts, if they're not keen on what they're seeing, festival-goers are likely to vote with their feet. Not to mention the odd boo or flung pint glass. Nothing daunted, Sadler's Wells performed Act II of Swan Lake on the lake stage at this year's Latitude festival and Ballet Black and the Royal Opera House also brought new work to Suffolk.
Bestival, though, will be the first time a ballet has been set to dance music. The six-strong cast will perform to tracks more often heard in clubs than at the Coliseum, in an upbeat mix which moves from epic (Faithless) to electro (Daft Punk) via a little Jacko and the theme tune from The Thunderbirds. In short, precisely the kind of quirky, fun tunes the notoriously hedonistic Bestival crowd will appreciate.
In keeping with the space theme of this year's festival, which will see the fields overrun by little green men, silver-clad cyber babes and Star Wars characters, the dancers have put together a futuristic take on the usual tights-and-tutu look. The girls will wear white-hooped mini-dresses and silver caps, and the boys will be bare-chested, in white cargo shorts with flashing green sunglasses. Both will start the set in extraordinary headpieces – towering long, white wigs, studded with coloured LEDs for the girls and Daft Punk-style robot masks for the boys.
Their Bestival appearance is a culture clash in more ways than one. The piece is built around a "ballet vocabulary": the ballerinas are on pointe, there are lifts, leaps and pirouettes, and the Thunderbirds section owes more than a little to Le Corsaire, albeit executed at a heightened pace to keep step with the increased bpm. Lee has also brought in Richard Essien, a B-boy she spotted performing in a club dance battle, who has added his own flavour to the piece with some pop and lock, breakdancing and robotic dancing. "It's been quite difficult, making it merge", admits Lee. "I'm not going to make Richard do ballet. And we're so drilled and trained, everything always has to be exactly the same as the girl in front. With B-boys, there are lots of improvised moves. To go on stage and not know what I'm doing next would be terrifying for me."
Aged 26 and in her eighth year at ENB, Lee has become the company's go-to girl for their more unusual projects, as well as dancing some of the most demanding classical roles in the repertoire. This month alone, she will dance in Ballets Russes on tour in Barcelona, and at Bestival, before taking up the powerful role of Myrtha, Queen of the Wilis ("the one who makes all the men who stray into the forest dance until they die") in the company's autumn tour of Giselle. She has also choreographed Ballet Rocks, a short ballet to music by Bloc Party with costumes by the fashion designer Giles Deacon for Sky Arts, and last year's A Beautiful Game, based on memorable moments in football history with England strips for costumes and routines riffing around on-and-off pitch antics from Maradona's "hand of God" to Gazza in the dentist's chair. The company also performed with Take That at 2007's Concert for Diana, in a Busby Berkeley showgirl routine, in stockings, lacy leotards and swimming caps.
The Bestival piece is a labour of love, rehearsed at night after long days in the studio practising pliés and fouettés. "For any dancer doing these outside projects, it gets your mind going", says Lee. "We're used to doing set pieces, so it wakes everything up again."
It's not just the dancers who can be revitalised by these hybrid experiments. A festival-goer might have his or her first taste of ballet, while ballet lovers are introduced to new music. Whether performed for the plush stalls or a muddy field, there's plenty of room for both.