Back To The Future | Barbican, London

It takes some doing to hold a healthy-sized Barbican audience in virtual suspension, but whatever you thought of Anne-Sophie Mutter's Back to the Future weekend recitals, one thing was for sure: she had us all hooked.

Charismatic is not the word. On Saturday night, Krzysztof Penderecki sat transfixed while Mutter tackled the hefty Violin Sonata that he had recently composed for her. Two huge keyboard clusters - one near the beginning of the piece, the other near the end - sat on the page as solid blocks. They were not typical. Penderecki's perplexing formula married Bartókian symmetry to a variety of chromaticism that even Bruckner would have found conducive. It is a huge, fervid, questioning piece that sets fin de siÿcle angst in a reassuringly tonal context. I doubt that a dozen or more encounters would reveal all its secrets, though Mutter's performance suggested that the effort might be worthwhile.

Anomalous as it is, Penderecki's Second Sonata pesters the memory in a way that Respighi's B minor Sonata of 1917 does not. Franck, Fauré, Brahms and Wagner were being recalled for service while contemporaries of Respighi prepared vastly stronger recipes elsewhere. Both Mutter and her superb pianist, Lambert Orkis, went at it hell for leather, though by then I was beginning to feel a little uncomfortable at what has become a fairly persistent mannerism in Mutter's playing. The sound itself is strong and luminous, the pitch mostly dead-centre. The main problem, as I hear it, is a vibrato that is conspicuous either by its insistence or by its absence, with virtually no grades of shading in between the two extremes.

Friday's Respighi put this trend on the line, but Saturday's account of the Shostakovich Second Piano Trio, where Mutter and Orkis were joined by the gifted young Munich-born cellist Daniel Müller-Schott, was stranger still. Arvo Pärt's Fratres had just ended among ethereal harmonics. In terms of sound, Shostakovich picks up where Pärt left off, though harmonics shift to the cello. The Trio's outer movements went swimmingly, but in the Largo, Mutter and Müller-Schott engaged in a stunned, wailing duet that banished vibrato with an almost ritual consistency. These were ghostly hounds baying from a corpse-ridden battlefield, quite unlike the human exchanges we usually hear. I hated it, but it did at least make me think.

Friday's recital opened with a performance of Webern's Four Pieces where Mutter and Orkis were as much the masters of musical silences as of notes on the page. George Crumb's exploratory Four Nocturnes had Orkis leaning over the keys to pluck - or fiddle with - the piano strings, while Mutter's fiddle traced delicate arabesques above him. Neither player seemed especially in the mood for Bartók's Second Sonata - the heat was on, but the arguments sounded oddly fragmented - and Mutter appeared to take no pleasure whatever in winding up Ravel's fiery Tzigane. Of course, her playing was technically fabulous, much as it was on the following night for Stravinsky's Suite on Themes, Fragments and Pieces by Giambattista Pergolesi. What a joy to write about someone who is individual enough to disagree with and bold enough in her repertory choices to have us contemplating the near past and wondering about the musical future.