CHOPIN: PRELUDES. Vladimir Feltsman, piano. CBS Masterworks M-39966. Feltsman's dramatic saga--when he applied for emigration from the Soviet Union in 1979, the authorities canceled his tours and curtailed most of his domestic activities--unleashed a storm of protest from Western colleagues. To judge from this recording made two years ago at the American embassy in Moscow, apparently with an invited audience, the Western world is much the poorer for the Soviets' intransigence. Feltsman sweeps through the 24 Preludes with genuine poetic bravura. One may occasionally fault his technique, his sporadic overpedaling and his reckless application of rubato, but there is a daring and Romantic fire in the playing which only add to the agony of his plight. The analog sound captures the piano with oppressive intimacy.