The sound of a French revolution

He is known to many as "the filthy-minded Frenchman", but another side to Serge Gainsbourg will be revealed at the Barbican later this year with the first live performance of his most influential album.

Gainsbourg made his name in the yé-yé tradition of France's take on Sixties pop, with hits such as "Bonnie et Clyde" and "Harley Davidson". His notoriety in the UK began when Jane Birkin breathed heavily over his No1 hit "Je t'aime... moi non plus". In the Eighties, he scandalised TV audiences when on a chat show he talked dirty to Whitney Houston.

Yet, in between, Gainsbourg showed himself to be a clever lyricist and innovative artist with a concept record that continues to influence musicians today. Nevertheless, were his ghost to be aware of the recent Monsieur Gainsbourg Revisited album, he might well be turning in his grave. Ever the sophisticate, Gainsbourg's sometimes excellent confections were habitually infused with ironic distance. So to hear the usually excellent Cat Power and Karen Elson knowingly revisiting "I Love You (Me Either)", Gainsbourg's arch musical tête-à-tête, is to experience more than a little ennui. Other interpreters of his songs on the set include Michael Stipe, Jarvis Cocker, Tricky, Franz Ferdinand and Jane Birkin.

Many years before this supposed trubute, Gainsbourg's early compositions had been revealing a literate mind and a playful musical touch. But nothing prepared his fans for Histoire De Melody Nelson. Released in 1971, its musical arrangements are so involved that they have never been performed live. At least, that is, until October when the BBC Concert Orchestra aims to recreate them. Lyrically, the set is just as ambitious, as Melody tells the story of the narrator's love affair with an English schoolgirl. A narrator in a Rolls Royce knocks Melody off her bike, seduces her, and enjoys a brief romance, cut short when she decides to return to her native Sunderland. Melody dies in a plane crash, possibly caused by narrator's evil thoughts. The album closes with one of the most haunting choral works heard outside of a Gregorian mass.

France's most celebrated songwriter died in 1991, so his vocal parts are to be sung by Jarvis Cocker, Damon "Badly Drawn Boy" Gough and the Super Furry Animals frontman Gruff Rhys, all fans of Gainsbourg's masterpiece.

Much of the importance of Melody is down to the work of its arranger Jean-Claude Vannier, an unsung hero until recent years, when he was rediscovered by DJs and hip-hop producers. His distinctive sound and that of similar Gallic mavericks are now currying favour on hip dancefloors from Manchester to Tokyo.

Known as jerk-beat, the French version of psychedelic funk has also been popularised by dance producers such as the Ocean's Eleven soundtrack composer David Holmes. Along the way, a select few vinyl explorers have uncovered another work by Vannier. While Melody relies on a spacious, bass-heavy sound to carry its Lolita-like tale, his own 1972 masterpiece L'Enfant Assassin des Mouches (the child assassin of flies), is a more disorientating proposition. Although instrumental, L'Enfant is held together by its own bizarre story, this time told in liner notes Gainsbourg wrote after its recording.

L'Enfant was originally only made available in 100 promo copies and in the vinyl-hungry Nineties it became the stuff of legend. Was it the same band that had recorded Melody? Had Vannier run off with out-takes from the recording sessions for Gainsbourg's masterpiece? Vannier, speaking from his Paris home, explains. "I became good friends with Serge after Melody until his death. He was very easy to work with, so I could write the music around the same time, but the two recordings were separate," he says. "I used the same choir, Jeunesse de France, but the other musicians were different. The band for Melody was recorded in London, while my album was all made in France. Melody was quite simple music, but L'Enfant was more about dissonance."

All this was revealed last year when L'Enfant became the debut reissue for Finders Keepers Records. The imprint was set up by, among others, Andy Votel, founder of Twisted Nerve, the Manchester-based label to which Gough originally signed, with the intention of tracking down such rare artefacts. It was a surprise for Vannier when his Mancunian fan got in touch.

"I did not believe him. I thought he was laughing at me," the French composer remembers. "L'Enfant did not get released because its producer was broke and I did not think the public would like it. They had ignored Melody and critics gave the same reaction, so that was very dispiriting. I knew Melody had become an important record for many young people, but I was surprised people remembered my own album."

Now this set too is to enjoy its live premiere on the same evening as Melody. It is an especially big ask to bring to life this work, featuring as it does bells, clocks, a model helicopter and billiard balls. So the Barbican has drafted in Vannier himself to conduct his own work and arrange its sonic menagerie.

"I want something for people to see as well as hear," he explains. "So I will have a children's string quartet and a musician to provide sound effects. He will break glass and I hope security will let us bring in the helicopter."

As for billiard balls, Vannier has decided table tennis balls make a better sound. For musical support, he is relying on some of the veteran session players that featured on the original Melody recording, among them a former Yardbirds sticksman, Dougie Wright, now a music teacher in Leicester.

Another musician whose career began in the Fifties is the session guitarist "Big" Jim Sullivan, who has played on something like 60 UK No 1 singles. He found time to record Melody in between touring with Tom Jones. Bassist Herbie Flowers can be heard on David Bowie's "Space Oddity" and Lou Reed's "Walk On The Wild Side".

It was only a few years ago that we were talking in the same excited tones about rediscovered the cult American producer David Axelrod, the man whose pioneering Sixties work provided beats galore for DJ Shadow. With Vannier, we are heading further into extremes of sonic experimentation, but underpinning his wild flights of fancy are consummate musicianship and intensely detailed arrangement.

Nothing was left to chance, not Gainsbourg and Birkin's tickling fight recorded for Melody nor the small army of sound effects marshalled for Vannier's own work. He and the Barbican have their work cut out.

'Histoire de Melody Nelson' and 'L'Enfant Assassin Des Mouches', Barbican, London EC2 (020-7638 8891; www.barbican.org.uk) 21 October. 'Monsieur Gainsbourg Revisited', an album of cover versions, is out now on Universal