THE Australian Chamber Orchestra made a big, bold, and rather brash debut appearance at the Edinburgh International Festival yesterday.

Brash? Well, in a way that word sums up their playing style, as exemplified in their sizzling and volatile opening performance of CPE Bach's little Sinfonia in B flat, which you almost sense was bracing itself for an assault. And the Australians don't half attack: they launched themselves into CPE's inoffensive wee piece, which, by the spirited finale, was beginning to cower.

I exaggerate, of course. The ACO players, led by their director and first violinist Richard Tognetti, have a big, big sound, very much in your face, big-boned and muscular; and the zesty musicians play up to the hilt, in an extrovert, almost outdoors manner, as though they have the wind in their collective face.

It can be extremely exhilarating to hear at full tilt. And nowhere yesterday was it more at full tilt than in Tognetti's arrangement of for string orchestra of Grieg's String Quartet. There's nothing new in such arrangements: the Scottish Ensemble is making something of a specialism out of this very game.

But in the Australians' hands the Grieg was a monster: a massive sound (think of Phil Spector's wall-of-sound techniques) with the low instruments coming up out of the floor while the music for the upper strings streaked into the ears.

Somewhere along this road it became clear that, as superficially thrilling as some of it was, there was really not much refinement or subtlety in the playing. And neither the meanderings of Vasks' Vox Amoris, nor the bendy-note textures of Scelsi's Anagamin added anything to the mix.