In the second of their public concerts at the lively MusicFest, the Karol Szymanowski Quartet showed just why they have gained a reputation as one of the most charismatic quartets of their generation, with playing of the highest calibre and string colours that were simply ravishing.

They opened their programme with Bartok's Third Quartet, among the most tightly focused of his works and, in its way, quite uncompromising. But, while making this a virtuoso demonstration of some of the unusual effects of bowing and pizzicato used by Bartok, the quartet's naturally lyrical tone infused warmth and ardour into music whose very compression into a single-movement structure sometimes appears to have had the humanity wrung out of it. This was a performance of astonishing intensity.

By way of leavening, the quartet was joined by saxophonist Gerard McChrystal for two contemporary works. In Edward Watson's Blue Remembered Hills, given its premiere here, the most interesting aspect of the broadly tonal soundscape was the soprano saxophone's engagement with each of the strings in turn, sometimes teasing, sometimes more confrontational.

When a haunting, cadenza-like cantilena from the sax elicited responses from the first violin - initially flowing, then more sinister and ghostly - the effect was disquieting and only somewhat resolved as the music evaporated into a gentle haze.

Nigel Wood's quintet So We Too - the name is a pun on its association with the Soweto Quartet - was the jazzy counterpart to the Watson. It was slight but witty, with McChrystal's exuberant alto sax indulging in a final swagger, but the cello just stealing his thunder.

The mood of intensity established in the Bartok was renewed in the second half when the quartet was joined by pianist Andrew Ball for Brahms's F minor Quintet Op 34. The players gave the piece a positively symphonic quality, unrelenting in its tension and gripping to the end. Whooping and cheering isn't the automatic response to Brahms's chamber music. But it was to this.