But what you get is maybe a little surprising. If Evelyn Glennie can be said to have "outed" percussion - as in out of the closet and into the ghetto - then the Safris are working towards ethnic integration. It's high time, they earnestly believe, that percussion was less of a side- show, less of a speciality act, an "entertainment". The music, not the hardware, comes first, they're saying, and anything you can do...
Their latest Chandos CD presents a typical Safri programme. Here's how it goes. You keep your custom-made set-pieces under wraps for the big finish. You start quiet and sophisticated with a little Bach. You proceed to Mendelssohn, Chopin, and Ravel... Hold on a minute, we are still talking percussion here? We are. Marimbas, actually. Two marimbas, four hands, three or even four mallets in each. That's 12 or 16 fingers, a head start on even the busiest keyboard counterpoint. It's an extraordinary instrument, the marimba, a happy alliance between the primitive and the futuristic. This soulful and soft-centred super-xylophone (actually a cross between a xylophone and a vibraphone) can warble and croon and percuss its way through an amazing spectrum of colours. Flexible and exotic, but hard- edged when needs be, it lends itself to a surprisingly wide range of repertoire. Small wonder it has all but transformed the fortunes of percussion as we know it. If percussion has a versatile singing voice, then this is it.
For the Safris, it's very much the centre of their universe, a way forward and a way back. Back to the future. Or Bach to the Future, as their compatriot Per Norgard would have it in a brand-new Concerto for Percussion and Orchestra scheduled for performance next year. That promises to be something of a landmark, not just for the Safris but for the Danish percussion tradition as a whole. Norgard - the father of that tradition (which came of age on the crest of Waves, his and Denmark's first piece for solo percussion) - shares the Safris' fascination with the past as a hot wire to the future. His Well-tempered Percussionists (also on the new CD) makes a whole new experience of Bach Preludes by merely re-phrasing them. Shift the bar lines, and you shift the whole perspective. Suddenly these venerable pieces are foretelling the rhythmic revolution of our own century.
The Safris play a lot of Bach. And they play it "straight". Not as straight as they used to, mind. In the beginning, they were, by their own admission, overly respectful. Inhibited. What would the Baroque purists make of them? What indeed. Enter their own friendly Baroque specialist. Liberate the music, he advised them, free up the expression, use the big dynamic range of the marimba. And so they started thinking beyond the instrument to the music. And that was the turning-point. "It shouldn't be about the instruments," says Uffe Savery triumphantly, "it should be about the music - always. Bach made many transcriptions for many different instruments; some of his music was composed with no specific instrument in mind. The notes are music in themselves. They are not dependent upon a specific instrument's character." Implying that if Bach had had access to a marimba as opposed to a clavichord... Well, why not?
"I suppose that, in the beginning, our work with classical transcriptions was, to some extent, experimental, educational. We wanted to transfer some of the traditions associated with this music to our contemporary repertoire. I think we realised that only through learning it, digesting it, understanding it completely - the way the lines worked, the shape, the structure - could we arrive at the highest level of musical expression. Because so much of the contemporary repertoire is complicated, because it is so hard just to play the notes, I think there's a tendency to concentrate on the notes at the expense of the music. So we were determined to bring the same approach, the same feeling, to contemporary music that we bring to Bach..." or Mendelssohn, or Chopin, or Ravel.
Ravel. Alborada del gracioso. The Safris' own transcription (for two marimbas) has become something of a calling card for them. Through the blur of flying mallets and swaying torsos, it's as if the piano version - enriched and magnified - has somehow been projected into another dimension. The effect is of some huge astral guitar picking and strumming its way through first light. The coolness and fluidity and luminosity of the sound would surely have captivated Ravel. So, too, the playing.
It's not the virtuosity of the Safris that so quickly transports you (though, heaven knows, that is staggering enough), but the musicality. From the heart, by heart. The seamlessness of their interaction is spooky: the split-second reflexes, the dovetailing of rubatos, the fine-tuning of dynamics - that's not just the fruit of exhaustive rehearsal, that's telepathy. You hear it, feel it, see it. The body language alone sets up tingling lines of communication. They don't even need to look at each other any more. There's an electromagnetic force at work here. They probably bend cutlery in their spare time.
Uffe and Morten have been "playmates" now since they marched together in the Tivoli Gardens Boys' Band. That comes as no surprise: a chemistry like theirs isn't manufactured, it just is. They fit. Uffe is the patient one, the thinker, negotiator, spokesman. He has to know exactly why he's doing what he is doing. He's the stabilising influence. Morten is more impulsive, the sparking-plug or ignition of the duo. Says what he thinks, when he thinks it. He's taught Uffe a thing or two about spontaneity. So they complement each other. They know it, their wives know it. It's "the other marriage", and so far so good. The Safri wives have been a part of the Duo from the start: they've come of age with the group, shared its growing pains. Morten says it wouldn't have worked any other way. It's very much a family affair.
But then, so was their musical education. Denmark has been home-sweet- home for percussionists ever since Bent Lylloff took over the faculty at the Royal Danish Academy of Music. He was the Academy's very first student in percussion; he effectively put percussion on the syllabus there; and he was super-quick on the uptake where the Safris were concerned. Together with their teacher, Max Leth, he helped develop what they now refer to as their "pianistic" approach to percussion - with special emphasis on the way in which tuned instruments like the marimba might integrate into a more "orchestral" texture involving drums, cymbals, gongs and so on (as witness a piece like Jacob ter Veldhuis's Goldrush, the title-track of their new CD). Again and again, though, the Safris will stress that they are less interested in expanding their arsenal of instruments and "special effects" than in expanding their musical vocabulary. They've the odd "theatrical" teaser up their sleeve (one project involving some well-tempered fireworks may well make it to Hampton Court - watch this space). But of much more immediate concern is the ongoing quest for new material: composers they can work with, transcriptions they can work on. Either way, they currently have a little money to spend - money for commissions, publicity, equipment (like their spanking new van) - thanks to a three- year appointment as Danish State Ensemble. How fitting that they should bang the drum for Copenhagen in this, her year as European City of Culture.
Meanwhile, in an empty harbour restaurant just outside Copenhagen, the interview is winding down. All around us, men and machines are winding up for the evening trade: a hand whisk in counterpoint with an electric processor, the chop-chop-chopping of busy hands punctuating the whirr of a calculator and the ring of a telephone. Funny how percussionists sharpen one's awareness of extraneous noise. Uffe and Morten look like they want to join in. Jam a little. The talking is over. The rhythm of life goes on.
n Safri Duo at City of London Festival: Thursday 7.30pm Guildhall Old Library, London EC2. Booking: 0171-638 8891