SIX close friends who are also London-based professionals have teamed up to present the five concerts in this year’s festival. Just how close was amply proved by their curtain-raiser, with music by Haydn, Mendelssohn and Schubert.

There is an extra frisson where ad hoc groups are concerned. Named ensembles have a reputation to protect, CDs to sell and promoters to please: caution rules. Not so here, when violinists Martyn Jackson and Magnus Johnston, viola player Sarah-Jane Bradley, festival director Tim Lowe, fellow cellist Pierre Doumenge and pianist Andrew Brownell gathered in York. No holds were barred, hearts were on sleeves and techniques stretched to the limit. Electrifying.

Haydn’s C major quartet, Op 74 No 1, written and premiered in London in the mid-1790s, is bursting with bold gestures. London loved it. We did too. Brimming with wit from the off, it climaxed with a breakneck Vivace which this group dispatched almost without breaking sweat.

Mendelssohn’s last quartet, Op 80 in F minor is arguably the most intense score he ever wrote. Only its slow lament offers a glimpse of warmth behind its anger. Here the opening was a cliff-hanger of tangled suspense, deeply unsettled, which accelerated immaculately into its final bars. Nor did the quartet shirk the composer’s stridency in the finale. This was a real tear-jerker.

Schubert’s Rosamunde quartet was equally, if slightly less polished. Though a little over-taut at the start, its Andante was allowed to breathe. Darker colours in the Allegretto turned brighter and more elegant in the lovely final rondo. What a start!

York Chamber Music Festival continues with further concerts today and tomorrow. Box office: 01904 658338 or at