In a world where there are scores of amazingly trained, virtually interchangeable violin virtuosos, Pekka Kuusisto stands out as that rarest of things: the genuinely individual talent.

It must be a dozen or so years ago now but I can still vividly recall the first time I heard him perform. A group of us aspiring teenage violinists had gone along to the Queen's Hall in Edinburgh, to hear the latest violin sensation making his Scottish debut, playing the Mendelssohn Concerto with the SCO. Kuusisto duly appeared, his playing every bit as accomplished as you'd expect from the first Finn to win the prestigious Sibelius Violin Competition.

Yet I found his performance disconcerting. This was the Mendelssohn as I'd never heard it before: gone was the gravitas, the weighty seriousness associated with such great music, to be replaced by a playful, puckish quality as if Kuusisto was making it up as he went along.

It wasn't until a couple of years later, when I heard Kuusisto again, this time playing one of the Prokofiev concertos with the SCO, that I appreciated just what I was hearing, the striking freshness of approach that spoke not of wilful iconoclasm just for the sake of being different, but of a considered, highly personal response to the music.

There aren't many violinists who play as he does and take the same risks. Then again, there aren't many classically trained virtuosos who would be in their comfort zone improvising with an electronic jazz group or taking the stage with a Norwegian noise duo. This other side of Kuusisto's musical accomplishments was made gloriously apparent at a memorable late-night concert at the East Neuk Festival a couple of years ago, where he performed a genre-crossing gig involving a host of styles from electronics and live sampling to traditional Finnish music in the novel surroundings of a Cold War-era nuclear bunker.

I met up with Kuusisto, now 32, in Glasgow last month. He was back in Scotland in a more conventional musical capacity, to give a couple of performances of the Eight Seasons (Vivaldi plus Piazzolla's Four Seasons of Buenos Aires) with the Scottish Ensemble.

"It's so funny how those things develop," he says of the standard violin repertoire over a bowl of cullen skink in the cafe at Glasgow's Centre for Contemporary Arts.

"With a concerto like the Mendelssohn, I'm incredibly aware of how people expect it to sound, but when you look at the original score you realise none of this stuff is actually written. With a piece like this, I think it's really important to figure out the ideal atmosphere and start from there - rather than listening to classic performance, which might be great but will be a very particular take."

The individuality of Kuusisto's playing seems entirely instinctive now, but it was, he says, hard won; not something he unlocked until after he'd finished his studies, first at the Sibelius Academy in Helsinki and later in Bloomington, Indiana.

"I was in Indiana for five years and I studied with violinist Miriam Fried, who has an incredibly strong, dominating personality," he explains. "She's a great player but everything she plays is unbelievably intense and focused. In some things she plays it's great but in others it feels kind of rigid.

"Her way of teaching was that she never wanted pupils to sound as she did - she wanted us to play our own way, but we had to explain every note. There had to be a reason; if you went and played something because someone had recorded it that way, it wouldn't be enough and if you imitated her then you would be in serious trouble."

Kuusisto returned from Indiana rather uncertain about what direction his playing should take. "I was starting to have a lot of work because I'd gone to the Sibelius Competition a year and a half earlier but it didn't feel so great," he recalls. "There were all these concerts I had - and really wanted - to do, but I wasn't sure what I was supposed to sound like."

The answer came from an introduction to Finnish folk music when a friend took Kuusisto to a traditional music festival. "I heard this fiddle group and they were so confident, with this incredibly natural way of playing. They were almost embarrassed to be on stage because they were enjoying it so much."

Somehow, this clicked with Kuusisto's own situation. "I hadn't been that much in touch with traditional music before but suddenly I felt I knew how to use this information from my teacher about how important it is to figure out your own sound. Coming from a country with a strong traditional music scene, it is really useful to be aware of it because I'm pretty certain that somewhere you're carrying it inside you. If you can find it, you have so much more foundation to your own playing."

This doesn't mean that Kuusisto plays the standard violin repertoire like it's Finnish fiddle music, but it has altered his perception of the relative importance of the beauty of sound in violin playing.

"Violinists spend so much time obsessing about the perfect sound," he says, "but it seems a fairly obvious thing that the pretty bits will only sound pretty if there is something else around for contrast." Listen to one of Kuusisto's recordings and you'll see what he means. He is capable of a range of sound that far transcends conventional ideas of pretty - from otherworldly to downright nasty. Far from being off-putting, it is the way in which he can communicate with his violin that makes his playing so compelling.

This approach is not without risks; put Kuusisto with an open-minded group of musicians and the results may be magical, but with an orchestra unwilling to depart from the bog-standard interpretation things are less happy. "Recently I played the Sibelius with the St Petersburg Philharmonic and I think I must have sounded so awful," he says, grimacing at the memory.

"Their playing was so lush and hyper-romantic and here I am scratching and scraping It's so difficult to challenge and it drives me crazy, especially if it's the conductor who is the source of the orchestral character. He's just waving his hands while I'm playing about a billion notes. When it comes to the Sibelius I think there are just a handful of people who've conducted it more times than I've played it, so they should at least listen to me. I know that if I can get everyone to see the way I feel it then it can be really powerful."

The sense of Kuusisto's playing as a musical journey shared perhaps explains why he connects so well with smaller groups far more flexible than a large-scale orchestra. This week he returns to Scotland to work with the Scottish Ensemble on its forthcoming tour with a programme that features Bartok's Divertimento and works by Estonian Erkki-Sven Tuur alongside works by three Finnish composers: Sibelius, Sallinen and Rautavaara. The ensemble performed the last's Fiddlers suite several seasons ago; here, however, Kuusisto will present it alongside the original Finnish fiddle tunes upon which it is based. The Finnish title of the piece, Pelimannet, has, he explains, been somewhat lost in translation.

"A pelimanni is not necessarily a violinist but a musician who doesn't care if this is the right moment to play. He doesn't obey the rules but just loves to play and communicate. Hopefully that's what we'll convey in our performance."

Pekka Kuusisto and the Scottish Ensemble play at Queen's Cross Church, Aberdeen, on Monday November 17 (part of the Sound Festival) then tour to Inverness, Dundee, Edinburgh, Perth and Glasgow. Visit www.scottishensemble.co.uk for further details.