A paradise of unnatural sounds

DJ Prichard G Jams was previously known as the Aphex Twin, whose real name is Richard D James. There's a new Aphex Twin album about to be released called Drukqs, and to mark the occasion Jams/Aphex/James will be making a rare appearance at the Elektronic festival at the Barbican in London on Sunday. But there's a problem. It's a late show and the Barbican residents do not want their beauty sleep to be disturbed. So, the 400-strong audience at the sell-out event will all be wearing wireless headphones. Novel, but it's going to be extremely weird walking into that space. The quietest gig ever.

It's no surprise that Mr Aphex is doing an event of this kind, turning, as he is, into a modern-day Brian Eno. He may resent the comment but there is mounting evidence to support it. Drukqs is a clever album in the same way that Eno's Another Green World is a clever album. It's well-informed, and refers to the work of "serious" composers and it will probably be hugely influential. In this latest offering the "serious" composer to whom James turns is John Cage, the man who invented the prepared piano. Screws, bolts, pencil rubbers and other objects are placed in the strings of a piano which is then played in the ordinary way. The result is an exotic, melodic, ping and rattle like a tiny Gamelan orchestra. James's new album presents several, meditative piano pieces, some of which use the sound of a prepared piano, scattered richly among the usual madcap, whizz-kid techno tracks.

The Cage reference is unusual because Mr Aphex normally cites European electronic composers as being his staple diet: Stockhausen, Xenakis, Berio – as well as the lesser-known Canadian and French "acousmatic" composers: Normandeau, Bayle and Parmegiani. Normandeau has an album on James's Rephlex label and Stockhausen is the main protagonist at the Elektronic festival.

Stockhausen is now 73, and began composing electronic music when it was made with bits of radio testing kit and grim determination. His seminal work Gesang der Jünglinge is being performed on Sunday evening; often considered, by those in the know, to be one of the finest pieces of electronic music ever made. It was composed in 1955-56 using sine waves and a recording of a chorister from Cologne cathedral. It is 13 minutes long, and took about 18 months to make. Vast bubbling clouds of sound wheel around the concert hall with the bright treble voice sometimes soaring, sometimes babbling and sometimes slicing through the ether.

William Orbit also makes a rare appearance at the festival. He made his name honing the sharp, techno edge on Madonna's Ray of Light album and has since gone on to produce Blur, All Saints and Beth Orton. He hasn't performed in London since he hosted an evening at the Queen Elizabeth Hall in 1995. And he has been quoted recently as describing Stockhausen as "Teutonic exactitude coupled with anarchistic bollocks". So how does he really connect with the king of the avant-garde?

"I meant it like 'it's the dog's bollocks'," he tells me. "I've got an enormous amount of respect for Stockhausen; he did it all first. His work is really provocative. I'm really impressed with the sounds." And which pieces in particular? "Mantra, Stimmung and Kontakte." Kontakte is being performed at the Barbican. It's classic Elektronische Musik, flown in from beyond the stars – a specially designed speaker system delivers a whirling vortex that throws bizarre, machine-made melodies from corner to corner.

So what is William Orbit going to do in this festival? It seems that this is a closely guarded secret, but rumour has it he has bought 200 tickets for his own show. He must have a lot of friends.

Music made with electronic devices began with Stockhausen and his colleagues in the early 1950s but before that film-makers were able to record sound on to optical soundtracks running along the edge of the film. A few daring directors and their sonic collaborators began cutting, splicing and looping these soundtracks to make experimental sound works to accompany their films. Cinema has always been an ideal partner for adventurous music. From Louis and Bebe Barron's electronic score for The Forbidden Planet through to the retina-warping underground films of the Sixties and Seventies, weird sound has always been more acceptable to the public when accompanied by visuals. This vast, and sadly neglected, body of work has not been overlooked at Elektronic, and a series of six programmes of Cinema of the Ear has been curated by Mark Webber. His day job is playing the guitar in Pulp but he's also established himself as a connoisseur of experimental film. "I came to it through the Velvets and Andy Warhol," he tells me. "There are parallels with the electronic music world and similar processes like editing, slow motion and stop-frame. Some film-makers use bits of scrap film – found footage – which is like sampling in a recording studio."

Standish Lawder's film Raindance, made in 1972, takes a tiny fragment of an old cartoon and, according to the director, it "plays directly on the mind through programatic simulation of the central nervous system. Individual frames of film are imprinted on the retina of the eye in a rhythm, sequence and intensity that corresponds to Alpha-Wave frequencies of the brain. Visions turn inward. The film directs our mental processes, controlling how we think as well as what we see. Images fuse with their after-images, colours arise from retinal release of exhausted nerve endings, forms dance across short-circuited synapses of the mind." All of this is accompanied by a hypnotic, early minimalist soundtrack. Total psychedelia. There's a Kenneth Anger film with Mick Jagger doodling a Moog synthesizer, films with shredded Beach Boys and Beatles and some very rare footage originally shown silently in the interval of a 1964 Stockhausen concert in New York and subsequently dubbed with the sound of the concert.

In addition to performances and film, there is a specially commissioned installation running throughout the festival made by Irmin Schmidt and his collaborator, Kumo. Schmidt was a music scholar in Cologne in the early 1960s and studied for some time with Stockhausen. Then he went on to form the seminal rock band Can. Schmidt and Kumo have installed a labyrinth of loudspeakers throughout the Barbican foyers where they will transform the ambient sounds of human conversation into insect laughter, layered with washes of celestial choral harmony and sharp, asymmetric rhythms. The installation is about transformations – of speech, of space and of perception.

This whole festival is about changing perceptions and bringing down the boundaries that used to separate high bourgeois culture from mass culture. In 1967, at the time his gargantuan work Hymnen was first being performed, Stockhausen wrote: "What I am trying to do, as far as I am aware of it, is to produce models that herald the stage after destruction. I'm trying to go beyond collage, hetrogeneity and pluralism, and to find unity; to produce music that brings us to the essential one. And that is going to be badly needed during the time of shocks and disasters that is going to come." A prophetic text given the times through which we are currently living.

Robert Worby's lecture 'This Is Stockhausen' is at 5.30pm on Saturday in Cinema 3 of the Barbican. The Elektronic festival continues until 18 October. Box office 020-7638 8891. www.barbican.org.uk