LAST summer at Amsterdam's Dekmantel Festival.

DJ and producer Laurent Garnier sidles up to the decks, headphones askew, a coy smile to the crowd, the sun streaming through the building, creating a golden halo around him as he starts to do his thing. Boom, the beats kick in. The crowd starts moving; Garnier's head starts nodding. One set of fingers drum on an imaginary keyboard, in sync with the pulsing music.

Then messages filter from brain to spine and his body, elbows out, starts undulating back and forth to the rhythm. His shoulders start twitching, his hands jerking quickly, as dials are masterly manipulated. By now, he's starting to sweat. He's in the zone. Fingers flick, flick, flick over the turntable, then a pause; he places his hand palm down for a split second, before, wham, the tune starts all over again.

You don't have to know Garnier, or even like house or techno music, to appreciate the focus, passion and sheer joy the Frenchman gets from plying his craft in a career spanning 27 years. He is arguably one of the most successful French musicians of all time, has been referred to as the European King of Techno - a sobriquet bestowed on him by many an electronic music aficionado - and has been touted as one of the world's best DJs.

Still, to dismiss Garnier's musical genres of choice as "not your thing" is to close your mind to a man whose influences and output are as multi-faceted as they are far reaching, and include everything from funk, jazz, disco and soul - the roots of House music - to dub-step, jungle, hip-hop, even classical. He has composed music for television, movies, ballets; is a prolific producer (he co-founded his label, F Communications, in 1994 ); has had his own radio show for over 25 years; and has co-written an autobiography that weaves the history of electronic music alongside his own life experiences. Aptly, he changes things up, is never static.

But above all, Garnier is a DJ, a role that sees him return next weekend to Glasgow. "I love going to Glasgow. I love Scotland," he tells me. He has friends here. He loves the crowd - "crazy, super-mad for it, enthusiastic, open-minded and ready to party" - and so always makes time to come to the city.

And at 48, Garnier is picky about where he plays. "I don't play as much as a lot of other DJs," he admits. "I've chosen to see my kid grow as well as be able to carry on my work. And I've never done it for the money - it's always been about the love of music." The decision to be selective came naturally. Scale back. Stay as excited as day one. Never get bored. "I thought it was a better solution to do less, but still be doing it with pleasure." (And he does: Garnier is renowned for getting into the groove of his sets as much as the crowd. "I love it," he whispers.)

"It's easy to drown yourself and do the same thing over and over again and get a bit dusty. And I don't want to do that," he continues. "I want to stay on the edge. So as much as I want to DJ, I still want to do other things." As well as releasing new music this year - "five EPs, in five different countries, on five different labels, in five styles of music" in a revolutionary "targeted" approach - Garnier has overseen the writing of a screenplay version of his book, which he is hoping to have made into a film next year. If all goes to plan, he will take a year off from being a DJ to be on the film set.

Until then, he refuses to do sets of less than two hours and prefers five-hour sets. "Because it allows me to express myself. My thing is to take people on a journey and I don't feel like I can take anybody on any kind of journey if I don't have time. It's a matter of writing a story."

No set is planned. It's about the mood, the place, the time. "Going with the flow. But taking them somewhere they wouldn't usually go. I want to push them. If you only have 90 minutes, you're only looking for a reaction."

A reaction would be easy, though. Garnier's most famous records, the ferocious Crispy Bacon (1997) and the jazz-heavy The Man With The Red Face (2000), are universal crowd-pleasers. And strong reactions feel good, he admits. "But the idea is to not just have them hands in the air; the idea is to keep them for as long as you can - and that's trickier. For me, it's more rewarding to have people stay for a five-hour session and at the end come up to me and say, 'I'll never forget this night.'"

Of course, scaling back his DJ gigs was also about being there for his 10-year-old son, Arthur, who is also the reason Garnier and his wife chose to move nine years ago from the city to the country, where they stay 30 minutes from Aix-en-Provence, to give him a better life.

Garnier's own childhood was spent growing up in the suburbs of Paris where, from age 10, he knew he wanted to use music to express himself. "I was picturing myself more on the radio. Then I discovered clubs and thought, 'Ah, this is what I want to do.' But I always knew I wanted to play music. That was very clear in my head." He turned his bedroom into a nightclub, complete with lights and disco ball.

But the restaurant business was like the family vocation. When he told his family he wanted to be a DJ, they scratched their heads, then sent him to catering school. By the end of the 1980s, Garnier was working as a waiter in London. But like a moth to a flame, he was drawn to Manchester, where Chicago house music had just arrived in clubs like the famous Hacienda.

With one record, Garnier's life changed. He found his genre. "It was the first house music track I ever heard - Farley Jackmaster Funk's Love Can't Turn Around. Mike Pickering played it at the Hacienda and it slapped me in the face so hard. It was what I had been looking for. It had the roots of everything I had been looking to - disco, jazz, funk, soul. I thought, 'This is it. I want to die now,'" he laughs. "And I just jumped into it straight away."

He sent in a demo tape to the club and was told to start in two weeks. "It was strange, exciting. From one day to the other I went from being a twice-a-week punter at the Hacienda to becoming a DJ in the place, telling people what was good music. I had never seen a proper turntable before."

The timing was impeccable. The Acid House scene was on the verge of exploding, rocketing Garnier's DJ career along with it. And then, like a needle screeching over a record, it was over. Garnier was called back to France for compulsory national service. When he came back a year later, it felt like he had missed the train. Frustrated, he went back to France, where Acid House was yet to take off. Second time around, he would spearhead the shake-up of Paris's hottest clubs.

Nearly 30 years later and Garnier remains at the heart of the electronic music scene in France and beyond. Ask him how he is feeling at this junction in his career, and he is candidly honest. "I can't lie to you. I'm asking myself a lot of questions. I'm going to be 50 in two years so it's normal and healthy for me as an artist to question myself. Am I still coherent playing music to a crowd that could all be my kids? Do I look like an old fart playing old-school music?''

Has he got the answers to his questions? "Yes, I'm still coherent and I don't look too old," he chuckles. "I'm still enjoying what I'm doing like the first day. I'm still buying tons of records. I'm still playing upfront music. But you have to stay on your toes. You have to share your love for music with the crowd - and I do. I still have things to say. Even after all these years, I sometimes surprise the crowd. So I can't lie to you, I'm feeling good."