You would expect a couple as venerable and seasoned as John Dankworth and Dame Cleo Laine to have a refined line in arch patter. Tonight, they do not disappoint. "Have you given any thought to what number you want to do, dear?" Dankworth asks at one point. "The one we rehearsed, darling," she barks in return, and the audience hoot delightedly.

In the first half, Dankworth, the saxophonist, performs a highly accomplished set with his quartet (including, joyously, his famous theme from Tomorrow's World). Yet as soon as his wife appears, he melts into the background like a well-drilled butler. It comes as no surprise to learn that this is precisely the role he pretends to occupy when fielding telephone interview requests for the pair. Dankworth's dry wit also comes to the fore when introducing his son Alec, who, we are told, is the fifth best double bassist in the little Buckinghamshire village of Wavendon.

The pair's music is as genial and engaging as their sense of humour: a blend of standards (Porter, Gershwin) and tunes written by band members, including historic material from the Dankworths' classic Shakespeare and All That Jazz album. Now in her 70s, Laine is still an astonishingly versatile singer, capable of eerily exact pitching and a range that many younger artists would die for. She still tackles songs as if they were succulent pieces of fruit, to he squeezed for every last drop of sense and emotion.

The band conduct themselves faultlessly, with trombonist Mark Nightingale scoring extra points for his agile soloing on Flood Warning, his ode to the local river Ouse. Pianist John Horler combines classical elegance with chromatic spikiness, while drummer Allan Ganley (an original member of Dankworth's 1950s big band) sizzles and swings; unexpectedly, he turns out to be the composer of a beautiful ballad about TV dinners. An evening of warmth, wit and surprises.