Svend Brown has been keeping an eye on the weather.

As director of the East Neuk Festival, he has reason to care: "The wonderful combination of music and place," he explains, "has been the bedrock of the festival since the beginning. East Neuk in the cold and wet? Well, the music sounds just as good. But the place doesn't feel half as festive."

We'll come to that music in a moment. The place is south-east Fife: its narrow-street fishing towns, its beautiful churches at Dunino and Kilrenny, Crail, St Monan's and Kilconquhar. For the past few years the late-June sun has shone strongly over this extraordinarily picturesque corner of the world and the festival atmosphere has been idyllic. "Fingers crossed," was all Brown could say a week ago, midsummer rain pattering at his office window.

But enough complaining about the weather. Tonight the eighth festival kicks off, rain or shine, and already the line-up looks to be vintage East Neuk. Five days of concerts will focus, basically, on very good chamber groups playing very good repertoires. With a core of Beethoven, Schubert and Mendelssohn, there's little to panic the flock – but enough novelty to keep things interesting.

Towering over the programme are two pillars of old-world string quartet tradition: the Leipzig from Germany and the Hagen from Austria. Anyone lucky enough to catch both over the next few days should be in for a fascinating point of comparison.

"Yes, both represent a great central-European heritage," says Brown, "but other than that I think they're like chalk and cheese.

"The Hagens are distinctive for the sheer beauty of their sound. It's lissom. It's fine and athletic, light and reedy – maybe akin to a gut-string period sensibility."

Performing two all-Beethoven programmes in Crail and Kilrenny, that lissom Hagen sound should be at its best.

"Then there's the Leipzigs," Brown continues, "who play with overwhelming muscularity. Their sound is seriously big – symphonic, really. And in a church like Kilrenny they will fill every single nook and cranny."

The Leipzigs play Beethoven, too (the glorious Opus 127), as well as Mendelssohn's Opus 44, Shostakovich's First Quartet, Schubert's Death and the Maiden and the Third Quartet by Jörg Widmann.

Brown is a self-proclaimed fan of the German composer/clarinettist Widmann: "To me he's one of the most interesting, emotionally penetrating and versatile composers working in Europe today. He's openly rooted in tradition, so fits with our programmes, yet his sound is totally new."

Widmann's five-string quartets make up a kind of cycle, each quartet functioning as one movement of a large-scale meta quartet. The third, which we'll be hearing this year, works as the scherzo. Does Brown have plans for a complete cycle, then? "In the pipeline!" is all he'll give away for now, but as he's already dreaming up not only next year's programme but festival's 10th anniversary in 2014, I'd guess that any Widmann fans should watch this space closely.

But back to this year's highlights. There's a Hildegard von Bingen programme from Paul Hillier's Theatre of Voices and medieval harpist Andrew Lawrence-King. There are two solo recitals from the young Scottish guitar star Sean Shibe and a concert of late Beethoven piano sonatas – Ops. 109, 110 and 111 – from Welsh pianist Llyr Williams. And, this being the eighth annual festival, there are octets by Haydn, Liszt, Stravinsky, Mozart, Schubert and Mendelssohn, directed by violinist Alexander Janiczek.

There's a new venue this year too: the excellently named Potato Barn at Cambo House. "I'm always on the hunt for spaces," says Brown. "We can use the Younger Hall in St Andrews, but the feedback from audiences is that they find it a shame to go into a normal concert hall after being in special venues. It's a bit like going back to school."

"So this year the Erskine family, the owners of Cambo Estate, mentioned that they have this barn. For most of the year it's full of potatoes, but in late June the crop hasn't yet been dug up - The acoustic has a four-second reverb, which hopefully will come down to two seconds with an audience installed. Add lights, toilets, projectors, seats – and voila! A new venue is born."

Also new this year is the festival's literature strand – or at least the extent of it. The development is in large part thanks to the involvement of Catherine Lockerbie, former director of the Edinburgh Book Festival and someone Brown describes as "brilliantly fascinated by the notion of heritage, landscapes and walkways". Together they've devised an immersive exploration of words and place: writer Sara Maitland discusses the Grimm Brothers during a guided woodland tour; poets Andrew Greig and Tom Pow wax lyrical in a pub in Anstruther; nature writer Richard Mabey leads a Sunday-morning stroll down the Fife coastal path. Keep those fingers crossed for a spot of sunshine.

The East Neuk Festival begins tonight and runs until Sunday.