In a land of midnight sun, there isn't much encouragement to go to bed - which explains why concerts at the Risor Festival run not only through the day but into the next morning; and why, at well past midnight last weekend, the pianist Leif Ove Andsnes was playing to an audience so tightly packed into Risor's 17th-century wooden church that it felt like rush-hour on the London Tube.
Andsnes and his fellow-Norwegian, the violist Lars Anders Tomter, are the artistic directors at Risor; and between them they've created a festival like no other - except, perhaps, Aldeburgh in its early days when Benjamin Britten managed, through friendship, to persuade the great and good of music to play in the modest circumstances of a remote seaside town. For the fun of it.
Risor, too, is a remote seaside town: a fishing community of weatherboarded houses set around a small harbour on Norway's south-eastern coast. Its concerts play against the cries of seagulls. And the artists are, effectively, a group of friends, who just happen to be some of the most celebrated names in chamber music, such as the baritone Matthias Goerne, the pianists Stephen Kovacevich and Paul Lewis, and the wonderful Belcea Quartet.
These artists don't just breeze through Risor with their summer touring programme. They stay for the duration, preparing repertoire on the spot in ad hoc groupings. And yes, the result can be seat-of-the pants, in ways that might be disastrous for lesser artists. But hearing Kovacevich and friends thunder through the Brahms F Minor Piano Quintet was the most bracing experience I've had all year, charged with a by no means flawless tension, and all the better for it. This was music as it happened, played like every note was life or death.
And it was the same when the Risor Festival Strings (drawn from principals in Nordic orchestras) played Britten's Variations on a Theme of Frank Bridge: heavily, with more weight than wit, but with a collective will that burst through the score like dynamite.
Not everything packed such a punch. There were moments of pure reflection in Paul Lewis's immaculate Schubert-playing; a considered argument for Sibelius's sometimes salon-sentimental piano works from Havard Gimse; and some memorable Bach and Brahms from Matthias Goerne, whose physical delivery (like a psychotic nightclub bouncer) was, as always, bizarrely at odds with the tenderness of his sound.
Tenderness, too, was the word for Leif Ove Andsnes's accompaniments. Playing for Goerne, and for a gossamer-light Winterreise with the tenor Christoph Genz, he was the complete musician: subtle, warm, imaginative, but able to accommodate his own sense of a score to that of a collaborator.
It was playing to cherish. As was that of less-known artists such as the French violinist David Grimal, whose mercurial tone (and personality) was an antidote to the high-gloss, machine-driven brilliance of a Vengerov or a Repin. But then, the whole ethos of this festival challenges current standards. At a time when so much music comes packaged in Cellophane - over-produced, remote and cool - Risor encourages a hands-on, intimate and generous directness. It's a joy. And, more's the pity, a one-off.