A breath of fresh Air: The masters of ambient Gallic pop return

Air are perhaps the world's most esoteric electro-pop act. There's the foppish, classically trained pianist Jean-Benoît Dunckel, with his delicate singing voice, slight frame and cryptic observations. Then there's his childhood friend Nicolas Godin, with his drawn cheeks, ginger stubble and mischievous retorts. When we meet, the latter chews gum feverishly and taps the table absent-mindedly. "I need to sleep for one week, then I will feel better," he says.

We're sitting in the lounge of the Portobello Hotel in west London. Dunckel and Godin are talking about their new album, Pocket Symphony, which is possibly the pair's most relaxed and cinematic work since their 1997 mini-album,Premiers Symptomes. Back then, they were seen as part of a new electronic movement in France, which centred largely on French house and the likes of Daft Punk and Cassius. In reality, they had more in common with their compatriots Jean Michel Jarre and the Moog pioneer Jean-Jacques Perrey. As such, they were embraced by the UK trip-hop scene and James Lavelle's Mo' Wax label in particular.

Air's first full-length opus, Moon Safari, which featured hit singles such as "Sexy Boy", rocketed to the top of the UK charts and helped them conquer the US. But their popularity wasn't quite as assured in France. "When we were working the demos for Moon Safari, no one in France understood what we were doing," recalls Dunckel. "To them, it sounded like soundtrack music with no beats. But the English media picked up on us, possibly because there were no new inventions in terms of music in the UK at that time."

"It was fresh," continues Godin. "With the French electronic scene at that time, most of it was house music, and some of it was crap. But no one was doing simply a kick [drum] with a synth pad. The parents probably thought it was horrible. But that's the aim of the young when they make music, and that was what was so cool with house music. If you go past the age of 20, you think there's nothing in it - exactly like older people felt about rock'n'roll in the Fifties. Nowadays, with this new wave of rock bands, I feel that the young are listening to the same music that their parents used to."

On their previous two albums, 10,000hz Legend and Talkie Walkie, Dunckel and Godin started to veer in a psychedelic-rock direction. "I regret that," says Godin. "I think it's not natural for us, even if we enjoyed it." Pocket Symphony was approached with "more feeling", and the result is the antithesis of the rock aesthetic. It has little in the way of hit singles - even if it does boast guest spots from Jarvis Cocker and the Divine Comedy's Neil Hannon - but it is a mature and exquisitely textured album that rewards repeated listening.

One reason for the change in direction was the experience of producing the actress Charlotte Gainsbourg's debut album, 5:55. Indeed, Pocket Symphony is the perfect companion piece to Gainsbourg's album. "Neil's song, 'Somewhere Between Waking and Sleeping', was taken directly from the Charlotte Gainsbourg sessions," says Godin. "In fact, it was done for her album, but she didn't use it. And Jarvis's track ["One Hell of a Party"] was originally intended for the Sofia Coppola movie Marie Antoinette, which is why Jarvis is singing about a decadent party." The track "Once upon a Time" was also meant for Coppola's film. "This is why the album is very soundtracky," explains Godin. "We were inspired by the movie. It was being shot while we were making it."

Pocket Symphony is Air's fourth album proper, but they are constantly working on other projects. "We make music all the time," says Godin. "You could also say that our soundtrack to The Virgin Suicides is an Air album. Sometimes it's a side project, but it's always the same process."

"There are projects you probably don't know about, such as work for TV and films," Dunckel continues. These include his fine solo electro-pop album Darkel, which slipped out largely unnoticed last September. "We had a lot of records and projects going on at the time," he says. "We were working like hell, but people were only aware of the big releases. Every three years, the record company wants an album. But it doesn't change the process. We go to the studio every day."

Other recent projects include music set to the ballet Near Life Experience by the acclaimed choreographer Angelin Preljocaj, and the "book-on-tape" album City Reading by Italy's most famous contemporary writer, Alessandro Baricco. This, like the new album, was produced by Nigel Godrich, who is best known for his work with Radiohead. "Nigel brings depth to our sound," says Godin. "He helped us be more direct in our compositions. For example, 10,000hz was very complicated, but he helped us to be more focused."

Surprisingly, the duo had never sung in French before they recorded new track "Mer du Japon". They believe English to be the Esperanto of the world, and think that French sounds too obvious. "It sounds stupid to us because it's really clear," says Dunckel. "If we could write lyrics like Serge Gainsbourg, then that would be fine, but we suffer from the weight of too much literature and poetry in France. Because we are not very good lyricists, we try to focus on a few key words to give a poetic attitude to the track. Also, I don't know why, but when I sing, it sounds like a girl - I think it gives a special, angelic taste to our music. If we'd have been lead singers at the beginning of our careers, we wouldn't have been able to treat our voices and use vocoders. We only did that because we had doubts about our abilities as singers, but it gave our music an amazing style."

The most unique addition to the Air sound is the use of Japanese instruments such as the koto (sometimes referred to as the Japanese floor harp) and the three-stringed, banjo-like shamisen, both played by Godin. He began to learn the instruments because of a "vision" after drinking too much champagne. "We called the Japanese embassy to find me a master, but it was very hard," he says. "They are traditional instruments and you need to show that you're sincere. They wanted to make sure that I wasn't going to make fun of it."

This new Japanese direction works best on "One Hell of a Party". Dunckel believes that Cocker's "crooner voice" works well with their "feminine way of doing music". When drawn on this observation, he equates Air's music to that of Chopin. "His music is something you can feel because of the way it breathes. It's really sophisticated. You feel the gentle curve of the melodies, you feel the counterpoint, the way the melodies are put together. In our music, it's the same. There's no tension in the writing. Because we are inspired by classical music, you get an ebb and flow that breathes in a very similar way."

'Pocket Symphony' is out now on Virgin. Air play ABC, Glasgow, on 14 March; Academy, Manchester, 15 March; and Forum, London NW5, on 16 & 17 March