It looks like an enormous droplet of mercury rippling alongside the Tyne - or, less charitably, a giant silver slug recoiling from a patch of salt.

But this was the first opportunity to hear inside the Sage, Gateshead's futuristic complex, as the Northern Sinfonia took residence in its £70m home designed by Foster and Partners.

What it sounds like is quite old fashioned, in the best possible sense.

Hall 1 (the 1,700 seat arena) rather bravely bucks a trend. It shies away from competing with the studio-like sonics of mega-halls in Manchester and Birmingham, and looks instead to the simpler, more intimate venues for which the classical repertory was originally conceived.

It is generally accepted that the two most acoustically perfect such venues in Europe are the Grösser Vereinsaal in Vienna and the Concertgebouw in Amsterdam. The Sage adopts the dimensions and capacity almost to the letter.

Their secret is that the upper two-thirds of the great Dutch and Viennese venues have decorative, reflective surfaces, while most modern halls are crammed with people. The Fosters team and Arup acoustic engineers have taken a bold step in keeping the dimensions intimate and boxy: it genuinely feels like a hall designed by acousticians rather than accountants.

It is custom-made for the Northern Sinfonia, a chamber band. The appointment of an inspirational Viennese music director, Thomas Zehetmair, two years ago lifted the Sinfonia's playing and bestowed an idiomatic command of the central European repertory.

Even an aircraft hangar was bound to be better than the old base at the Newcastle City Hall; but the Sinfonia emerges resplendent in the warm, reverberent acoustic of its new home.

Zehetmair's choice for the inaugural concert is Haydn's Creation: a central pillar of the classical tradition which reaches back to Handel in its context, and foreshadows Wagner in its tonal audacity. It also gives the impressive, albeit suitably modest, forces of the Sinfonia Chorus an opportunity to raise the rafters.

The Sinfonia has, in all honesty, turned in more freely expressive performances than this: there were some slightly frayed nerves at the beginning and even a muted sense of being overwhelmed by the occasion. But Gateshead will have a world-class chamber ensemble inhabiting its truly world-class chamber.