The excellence of the academy's performance on Saturday gave further proof of its remarkable improvement over recent years.

Under its tireless founder-director John Hastie, York's only chamber orchestra (outside the university) played a concerto and symphony by Mozart, preceded by a Walton taster.

The strings undoubtedly received a huge fillip from the presence of Jonathan Sparey and Alan George as soloists in Mozart's Sinfonia Concertante for violin and viola, not least because both joined in the orchestral tutti. Not all soloists bother.

The teasing first-movement cadenza gave immediate evidence of the pair's easy familiarity, as did their conversational exuberance in the finale.

George was playing, for the first time in public, a viola built for him last year by his father-in-law, Wolfgang Marc Schatzberger.

The instrument's rich quality was especially apparent near the start of the Andante, enhancing the movement's soulfulness.

The orchestra gave vivid support throughout the work.

String confidence continued at a high level in Mozart's K.550 Symphony, No 40 in G minor.

The opening Allegro made up in brio what it sometimes lacked in finesse, but a neat start to the Andante heralded a return to well-rounded ensemble.

The finale danced happily, the violin phrases offering a twinkling contrast to the woodwind's more boisterous punctuation.

Walton's little Siesta, in the style of his Faade and also originating from 1926, made an unusual starter, seeming to take the orchestra somewhat by surprise. But the Mozart more than compensated.