LSO / Previn, Barbican Hall, London

It doesn't seem so very long ago (but it was) that André Previn crossed over from the darkside (aka Hollywood) and sought the classical limelight in London. He sported a Beatles haircut and a spring in his step, and Eric Morecambe called him Mr Preview.

The twinkle in his eye hasn't gone, but the spring in his step has and, approaching the podium as gingerly as he does his 80th birthday next year, it is a frail Previn who sits before the orchestra he made so very much his own – the London Symphony.

But Previn's passion for this orchestra and for the music they share remains undiminished, and if you watch him carefully you'll see in the old hand gestures that the musical perceptions are as sharp as ever. In the Suite from Strauss's Der Rosenkavalier, subversive harmonies brought a clear physical response with the familiar shake of the left hand greatly intensifying vibrato and encouraging strings to sing out. Pyrotechnical horn descants were equally favoured. It's a composerly way he has of acknowledging this detail or that, and now that he is spending more time on his own pieces, it was only fitting that he bring one along.

The Double Concerto for Violin and Contrabass dates from 2004, and has never been aired in Europe. It's interesting to hear how Previn's recent compositions more openly reflect his private enthusiasms – such as Erich Korngold, whose hothouse lyricism permeates almost every fibre of this lively, entertaining piece. There's Walton in there, too, and a piccolo solo on loan from Shostakovich. But the lush palette of harmonies is pure Hollywood Korngold, and the fun lies in subverting expectations as to how the "little and large" solo parts pan out.

Rather cheekily, it's the contrabass – dazzlingly played here by the Slovakian Roman Patkolo – who gruffly gets to whisper most of the sweet nothings to his amorous partner – Anne-Sophie Mutter. Ungainly he may be (this is, after all, a kind of Beauty and the Beast set-up), but under the fingers of this amazing player, beauty and agility are a given. So who's the beast now?

Earlier, Mutter reminded us that hers is still the most seductive sound in the business when she played the socks off Mozart's Violin Concerto No 3, raising smiles at the appearance of a corpulent, over-rouged gavotte in the finale. Previn, who openly espouses the Viennese style, and did so benevolently, if rather sedately at times, in Haydn's "London Symphony", enjoyed pointing up its vulgarity.