It was near midnight on a cold Orcadian midsummer when I first encountered the violinist Hugo Ticciati.

He was playing a solo recital in Kirkwall's St Magnus Cathedral - a magical setting for concerts, built by 12th-century Viking earls in thick-set red sandstone and one of the most miraculous church acoustics in the country. Inside the lights were dimmed low for the late-night performance, but outside the northern summer gloaming still lit the sky and the cathedral's stained glass panels were glowing. Before the concert I spotted Ticciati standing by the altar, head cocked to one side. He looked as though he was tuning into the atmosphere of the place.

Ticciati's programme that night was risky: a musical stream-of-consciousness (or, his term, a "dialogical flow of music") that mixed Bach's monumental Chaconne with fragments of Arvo Part, Akira Miyoshi, Nigel Clarke and his own improvisations. He played continuously for an hour, starting at the front of the audience then roaming the floor to find the building's most resonant corners. There was considerable scope for the performance to become indulgent or incongruous or plain boring - yet it was among the most mesmerising hours of live music I experienced last year.

Turns out it was typical Ticciati: a musician for whom the mechanics of playing the violin are just a small part of his singular artistic philosophy; for whom the mindfulness and chance occurrences that stem from that "dialogical flow" are fundamental not just to his music making but to his whole life outlook.

I arranged to meet Ticciati for coffee the following day, keen to investigate his intriguing approach to programme and, I'll admit, curious to meet the older brother of Robin - a musician whom Scottish audiences have got to know well since he became principal conductor of the Scottish Chamber Orchestra while still in his twenties. Next morning I found Hugo reading through scores at his hotel down on Kirkwall's harbour front. With a long mop of hair dangling in his eyes, round horn-rimmed glasses and baggy red corduroys, he looked both in and out of place in the faded establishment: an authorly figment from the 1970s, maybe, with a touch of the George Mackay Brown about his worn woolly jumper.

My plan had been to talk there, looking out over the grey sea and the diving birds, but our conversation soon threw a serious curve ball. Ticciati hadn't yet visited the Ring of Brodgar, nor was he aware of any of Orkney's neolithic sites. "You see," he explained apologetically, "sometimes I'm just too caught up in my scores to notice what's around me."

So we ditched the hotel, got into my car and drove the straight, open roads westward to the stones at Brodgar. Along the way Ticciati told me about his upbringing. He was born in London, his father a barrister, his mother a therapist, their house full of music and impromptu chamber ensembles. As a teenager he was a formidably talented violinist, but he also explored spirituality and, independently of his family, became an evangelical Christian for a time. He suffered physical strains from too much practising. When he was on the verge of taking up an undergraduate place at Cambridge he met Nina Balabina, a Russian violin teacher who lived in the forested outskirts of Stockholm.

"Within five minutes I knew that I needed to spend a lot of time with her," Ticciati recalled. "So I turned down Cambridge. Everyone thought I was mad, except my dad, but I knew it was the only thing to do."

He moved to Sweden in 1998, living with Balabina, speaking only Russian and Swedish and rebuilding his violin technique from scratch. "Some days I would only pick up the instrument and not play it; other days I would spend 40 minutes working on vibrato alone." The regime lasted for three years, a complete re-boot, spiritual as well as technical. He discovered Zen philosophy and meditation. He didn't play in public; he hardly even went into central Stockholm. The word he uses now to describe that period of his life is 'hermitude'.

Eventually the hermitude began to soften. A friend asked him to give a lecture about classical form and the early symphony to students at a specialist music school in Stockholm, and he loved the experience - "clearly the time was right for me to emerge, blinking into the light!" he joked. Life began opening up from there. He hired an agent; his career took off. Now he describes the music industry as a game he has to play, "like Monopoly".

He has also started performing in the UK again: this summer alone he plays at London's King's Place and Wigmore Hall and gives two performances at Fife's East Neuk Festival. The sudden surge in British appearances is notable, given he had more or less cut musical ties here since moving to Sweden. I asked whether that break had anything to do with a feeling that London was his brother's artistic territory; Robin is music director of Glyndebourne, a regular guest with the London Symphony Orchestra - he could hardly have made Ticciati a more visible surname in British classical music. Hugo pondered the question, then eventually agreed that it felt healthier to "let our careers develop apart".

By this point we had arrived at the Ring of Brodgar, left the car at the side of the road and climbed the gentle bank up to the stones. The wind was biting and the horizon full of dark, spitting clouds, but Ticciati seemed unperturbed. "Marvellous!" he exclaimed, and set off striding around the circle with hands clasped behind him and coat billowing in the gale.

On the drive back to Kirkwall we talked about his other major preoccupation: the annual festival he runs in Stockholm called O/Modernt. The name translates as 'un-modern', and the programme, centred around an original rococo theatre, combines early and contemporary music with elements of improvisation, dance, jazz and plenty else. But it's more than token genre-bending. Just like his solo recital's fluid segues between Bach, Part, Miyoshi and earthy long notes, Ticciati's festival line-up is a lens into his holistic musical approach. Stockhausen's Stimmung might rub shoulders with Reich, Rameau and hip hop.

"We're playing with old music in a fun and serious way," Ticciati told me. In this year's Scarlatti-themed festival, one evening cut from Part's Spiegel im Spiegel to a Japanese Zen dancer balancing with a feather. Then the musicians played the whole programme again - backwards.

This year's East Neuk Festival showcases various facets of Ticciati's musical personality. In his second concert he directs the Scottish Chamber Orchestra in a programme that he refuses to quite pin down: it opens with Lera Auerbach's Sogno di Stabat Mater, a work inspired by Pergelesi, then moves on to the Four Seasons of both Vivaldi and Astor Piazzolla. In a recent interview with ENF director Svend Brown, Ticciati suggested that something else might well crop up between the Vivaldi and the Piazzolla but that he couldn't predict what. Even when working with an orchestra, he reserves the right to that dialogical flow. "When one approaches things undecided, without having put things in a box, things can happen," he told a slightly nervous-looking Brown.

His other East Neuk appearance is a recital at Dunino, a tiny church perched above a lush river inland valley, off the beaten track from the prettified coastal villages where most of ENF takes place. The solo programme revolves around Bach, similar to the one I heard in Orkney last year, and includes Karin Rehnqvist's Klockrent for 100 ancient church bells. "There's something very naked about being there," Ticciati said when I asked about the experience of solo playing. "There's an intimacy to being on a stage on one's own, and I'm enticed by that. It forces me to be totally open and not hide anything. It's just me and my sound, which is incredibly intense."

I remarked on how composed he had looked during that Kirkwall performance, how he had exuded absolute serenity even when his bow hairs were shredded and his strings needed re-tuning in the middle of a movement. "Ah, maybe that's because performance is like meditation for me," he replied. "When I come on stage I enter this peaceful space, but it's combined with enormous adrenalin. I'm bubbling with nerves and energy, but at the same time I think about my breathing and let my thoughts disappear. I just play. All of that intensifies when I'm on my own on stage. Everything I do is under the microscope. When my bow hair broke, I had to think about how to weave that in. Or the tuning. When I realised that my strings were slipping, I simply tried to make the re-tuning part of the music."

He paused. We were now back in Kirkwall harbour, the car parked to face the off-duty fishing boats. "Ultimately," he said, "performance has to be about dealing with music in real time, and about responding to the situation in a way that is totally present. I'm glad we went to see the stones."

Hugo Ticciati plays a solo recital at Dunino Church on June 29 and leads the Scottish Chamber Orchestra at Cambo Barn on July 1, both part of the East Neuk Festival, www.eastneukfestival.com