When he exploded on to the international scene 30 years ago, Maurizio Pollini played lots of Schumann - Etudes Symphoniques, the F sharp minor Sonata, the C major Fantasy - and played it peerlessly, combining rigour and imagination in exactly the right proportions. Since then, in his London appearances at least, he has tended towards other composers, especially Beethoven, but in his two recitals at the Festival Hall this season he has returned to Schumann, and to some neglected pieces at that. Next April he is due to play the early Allegro Op 8 alongside Kreisleriana; here he gave a rare outing to the Concert sans Orchestre, also known as the Sonata No 3 in F minor, Op 14. It is a strange work, both wonderful and unsatisfactory, another part of the great outpouring of piano music from the late 1830s, when Schumann was forcibly separated from Clara Wieck. He later revised and expanded it, but Pollini played the first published version in three movements built around a central set of variations on a theme by Clara herself - the emotional heart of the work. The first movement is an embattled conflict between Schumann's natural flights of fantasy and his determination to tackle sonata form, the finale a brilliant Presto, written as a tribute to the great virtuoso Moscheles, and as demanding as anything he wrote. The F minor Sonata is the kind of piece that needs a Pollini, someone to take a grip on the structure yet master all its technical challenges, and he did exactly that. It had been prefaced by more Schumann, the Davidsbundlertanze, in which Pollini had seemed surprisingly nervous, pushing through lyrical movements when they cried out for expansiveness, never allowing the effect of one magical phrase to settle before launching into the next, and sometimes understating the melodies that well up beneath dazzling figuration. Liszt followed. The B minor Sonata - prefaced by a pair of the late short pieces, Nuages Gris and La Lugubre Gondola, long-time Pollini favourites - was immense, ferociously precise, intense and insistent in the slow movement, and superhumanly fast in the climactic double fugue, a performance of take-it-or-leave-it integrity. The encores were Chopin - the D minor Prelude, glittering, turbulent; and a Nocturne, sung with wonderful purity of line. Altogether one of Pollini's finest recent London recitals.