It may be considered desirably authentic to direct classical piano concertos from the keyboard but, as various visitors to the QEH have shown, sometimes the more a pianist focuses on conducting, the worse his own performance gets. Imogen Cooper has the right idea in her collaborations with the Britten Sinfonia: no arm-waving save the odd low-key gesture but, in its place, detailed rehearsal and a good deal of eye contact.

That last certainly seemed to be the secret behind the outstanding quality of the Sinfonia's performance here. With the orchestra, led by violinist Jacqueline Shave, playing like a true chamber ensemble, the long introductions to the opening movements of the two piano concertos were some of the evening's best moments, displaying a unanimity of purpose, blended sound and breadth of tone you don't often hear even under the best of conductors.

In the Concerto No 1, the crispness of Cooper's response was occasionally blurred by sluggish pedalling, but she matched the orchestra's energy, and was at her best duetting with the clarinet in the dreamy slow movement. The Concerto No 2 brought more opportunities for direct interaction between piano and orchestra. Cooper has a firm touch that can veer towards harshness, but she controlled the slowly receding close of the slow movement with such poise that it was followed by seconds of rapt silence, and the dancing finale brought the concert to a good-humoured close.

In between came something less familiar, the brief but colourful Rondino for wind octet. It further showcased the quality of the Sinfonia's wind section - not only is oboist Nicholas Daniel of soloist standing here but the horns that led the music into the distance at the end, transforming a hunting-style call into a whispered echo.