As a performer, Italian violinist Uto Ughi certainly is not a man of great miens. Last evening at the Library of Congress' Coolidge Auditorium, his demeanor--whether outlining the dignified theme of the Sarabande from J.S. Bach's Partita in D Minor or the agitated melody in the final movement of Brahms' Sonata in D Minor--was one of total absorption, devoid of any superfluous animation.

Ughi's playing, on the other hand, communicated immediacy and gusto. Thanks to a strong, yet supple bowing arm (and his Van Houten-Kreutzer Stradivari violin), he seemed incapable of producing anything less than a flawless tone.

As a soloist in the Bach Partita, he added an extra dollop of color to the rapid single line and deliberate double-stop melodic strands. Ughi and pianist Jonathan Feldman's traversal of Beethoven's Sonata in F Major ("Spring") was almost an embarrassment of riches--too much intensity, with little room for contrast.

Their partnership was most effective in the Brahms sonata, a work conceived with the violin and piano on equal footing. The tempestuous fast movements bracketed the lovely Adagio, which spotlighted Feldman's liquid phrasing and Ughi's natural portamento.

For a well-deserved encore, they launched into Sarasate's Zigeunerweisen, a work teeming with acrobatic violin maneuvers. Ughi soared through them, as he and Feldman operated at breakneck speed.