Last night at the Library of Congress cellist Harry Clark and pianist Sanda Schuldmann offered an evening, all too rare in these superstar times, when the music came first. Playing with exceptional unity and sensitivity, this husband and wife team proved an ideal servant of the composers, including Benjamin Lees who was present for the premiere of his Sonata.

The second of three pieces that Lees has written for the duo, the Sonata reflected careful craftsmanship applied to a thorough exploration of the chosen musical materials. Despite some passages of beauty and intensity, the overall effect lacked force. Though Lees worked through his ideas with an almost relentless curiosity, he failed to find their emotional center. For all their density, the results left the listener feeling unsatisfied.

The surrounding selections, given marvelously fluid interpretations by Clark and Schuldmann, offered more than ample compensation. The duo entered fully into the romantic sensibility of Schumann's "Phantasiestu cke, Op. 73," handling its mercurial shifts of mood with beguiling ease. Faure''s "Ele'gie" revealed Clark's elegant line and Schuldmann's delicate control of touch. Together, they made the closing C-Major Sonata of Prokofiev glow, as Clark breathed warm and supple life into the long phrases and Schuldmann underlined the intensity of the passionate themes.