LENOX -- If Beethoven wrestles with angels in his last three piano sonatas, Schubert walks among them, heedless, in his last three.

Paul Lewis strode onto the stage in an ivory-colored shirt at Tanglewood Wednesday night and, barely acknowledging the applause, tore into the first of the Schubert set, the C minor, as if possessed by demons. The Ozawa Hall stage was bare except for him and the Steinway; the risers had been removed.

Bare, that is except for a slender, bushy-haired Englishman who, on a moonlit night, immersed himself in the innermost yearnings of these three masterworks and brought back the messages from afar. When the second theme emerged from the tumult of the opening, it seemed a breath from a world better than ours.

An evening of these works, like an evening of Beethoven's last three, is almost too much, and indeed, Lewis looked exhausted at the end. But who would want less?

There are, of course, lighter moments in these works. The middle sonata, in A, teases you into thinking you're with the gentler Schubert - the Schubert of some of the songs, for example.

But no. The slow movement, daydreaming along but punctuated by angry chords, became a farewell to earthly cares and joys. Then, in the sonata's finale, Schubert breaks your heart with thematic recollections that alternate between serenity and turmoil. Are you in heaven or in hell?

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The wonder, of course, is that Schubert poured out these and some of his other greatest works in the two years before his death at 31. But Lewis, who made his Tanglewood debut last year, knows the territory well. For the past two seasons, he has devoted himself to Schubert's late piano works, and specifically to the program of last sonatas, which he has played 45 times in Europe and the United States in the last year alone.

Schubert modulates often, and often to far-away keys, and Lewis rode the changes like waves, making them seem not only natural but also surprisingly right and true. Similarly, tempo and rhythm were in constant flux, but always they followed and enlarged the course of the music. Think of a river, always flowing, now faster, now slower, now eddying, now nearing shore, now turning away and back on itself.

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The ferocity of fast movements, the calls from another world in slow movements, especially in the hauntingly decorated returns of themes: These all too human, yet greater than human, gestures culminated in the B-flat sonata. Its broadly scaled opening movements, with the first movement's mystic rumbles in the bass, led to apparent good cheer in the finale, only for the cheer to be undermined by shifts of harmony and dynamics that longed for a peace that was out there somewhere, if only we humans could

There was no encore. There was no need for one.