'Actually, there's a nice wee story that sums this up perfectly." Susan Tomes is giving a spiel she's been through many times before, to do with why and how modern phraseology treats pianists as dogsbodies.

"The great Robert Levin was once asked whether he would called himself an accompanist. 'No,' he answered, 'because I do not play the accompano.'."

If the distinction seems a tad pedantic, reel back a couple of hundred years to see that things were not ever thus. Until well into the 19th century, pianists were revered as equal to their string partners in chamber music, or even the main event. The notion of accompanists as a disposable back-up band came later – the fault of conservatoires, Tomes suggests, when classes of violinists would play through sonatas sharing one pianist to fill in the blanks. As touring virtuosos of the Paganini generation took up more and more of the limelight, their pianists shrank into the shadows.

Tomes's current concert series at Perth Concert Hall aims to restore some of the balance by exploring Mozart "from the piano out", drawing pointed attention to the order of his Sonatas for Piano and Violin. "The piano is the key speaker in these pieces," she says, "while the violin partner plays antagonist or commentator." Did Erich Höbarth, Tomes's violin partner for the Perth series, object to being billed as "commentator"? "No. He's too intelligent a musician to object. He knows it's the right approach."

As one of the UK's leading chamber music pianists, Tomes is likewise probably best classed as an "intelligent musician". Born and raised in Edinburgh, she took lessons at the Royal Conservatoire of Scotland's Saturday school before becoming the first woman to study music at King's College, Cambridge. "It was the first wave of equal-opportunity experiments," she says, "and a lesson in surviving extreme social environments. Men instantly fell in love with us or totally resented us for being there at all."

After graduating, she co-founded Domus, a touring piano quartet with a twist: a geodesic dome that could pop up for concerts wherever they went, like a mini travelling circus tent for chamber music. It was during the Domus years that Tomes started writing. What began as a private diary about the day-to-day of touring eventually became her first book, Beyond The Notes.

"I find writing good for me," she says. "The process helps sort out my thoughts – stay on an even keel. Playing music all the time can edge you off-centre -"

Now the author of three books, Tomes's blog is a resolve to demystify the logistics of life as a classical musician. "It's sad that people know so little about how we operate," she says. "After concerts I get asked 'Is this all you do, or do you have a job as well?' or 'Do you ever get together and play other than in performances?' . People think that music is a gift that you've got or not. Apparently, if you've got it, you're supposed to just sit down and do it.

"Of course, nobody will ever demystify music altogether. It is a mysterious art by nature, which is part of its beauty. I just hope that if people like me write, we might offer a glimpse into making it happen."

A major portion of Tomes's philosophy was formed under Hungarian violinist and pedagogue Sándor Végh at his legendary workshops at Prussia Cove in Cornwall. He died in 1997 but his legacy looms large in UK chamber music circles, as Tomes explains: "Music had to speak, he'd tell us. Not just beautifully, but about every facet of life – lovely, brutal, remote – as comprehensive as any language. It was liberating stuff. Too often music is treated as an accomplishment or an adornment.

"Even then, in the early 1980s, Végh was afraid of what was going to happen to playing styles. He used to bore us to death with his gloomy prophesies. 'Watch out for the trend from the America,' he'd say, meaning polished, superficial playing designed for projecting into large halls rather than intimate spaces. His phrase was 'pouring too much sauce over everything so it all tastes the same'. Now we're realising the truth of what he said. I hear that kind of playing everywhere."

It was at Prussia Cove that Tomes first met Höbarth, who was working as Végh's teaching assistant at the time. They recognised each other as "kindred musical spirits" and vowed to work together, then each set off on careers that left little time for side projects: he as leader of the Vienna Sextet, Quatuor Mosaïques and Concentus Musicus Wein, her as pianist of Domus, the Gaudier Ensemble and, for the past 16 years, the Florestan Trio. In that respect, the Perth collaboration has been a long time coming. "Erich is Viennese in the best possible way," Tomes says. "Music is meat and drink to him. I recently asked him whether he'd learned to use a computer yet. He replied that he'd prefer to spend his time studying Bach cantatas. Brilliant!"

They rehearsed the Mozart series in Vienna – where else? – and although "it may sound twee," says Tomes, "there's something in the air there that makes this music feel natural. For breaks we'd look out places that Mozart went for coffee and billiards". Twee or not, the results have been breathtaking. Their first concert offered early Mozart at his most elegant, breezy and deeply conversational. If any playing could pay proper homage to Végh's teachings, this would be it.

With nearly 20 works divvied up across the four programmes, this is the most immersive single-composer project Tomes has taken on. Like most pianists who play Perth Concert Hall, she reports a special affection for the piano there: even sound, responsive touch, and a general acoustic that allows the detail of her phrasing to be heard without forcing it. Just as well, she says, "because, with Mozart, the challenge is that everything has to be perfectly, clearly articulated. Effects in Romantic repertoire can be made through more general gestures, but Mozart demands total dexterity.

"There were moments during rehearsals when I wondered whether I'd be able to keep up the definition across so much music. But the challenge has already had a fantastic effect on the way I play other music, and on me personally. Mozart's music is utterly balanced. If he writes a phrase that goes up, the following phrase will come down. If he's sorrowful in one passage, he'll respond with joy the next. Good for the brain, somehow."

Susan Tomes and Erich Höbarth continue their series of Mozart for Piano and Violin at Perth Concert Hall on December 14, February 25 and May 2, www.horsecross.co.uk, 01738 621 031.