As we move toward the end of this century, our perspective allows us to sort out the music of 60 and 70 years ago, to understand the directions musical developments were taking and to place what was going on in context.

For Friday night's program, the second in this year's Library of Congress Festival of American Chamber Music, violinist David Sackson and pianist Leon Pommers brought a repertoire of conservative pieces from the first half of the century. John Alden Carpenter's Sonata, an effusive, almost gushing work, is straight out of central Europe -- an overripe example of an idiom that has seen better days. Henry Cowell's Suite, with its roots further back in a Baroque tradition, was more restrained but essentially characterless in its self-conscious eclecticism.

The real character in the program came in George Antheil's puckish Sonatina with its overtones of Prokofiev and in Robert Russell Bennett's "Hexapoda" for violin and piano, a set of five explorations of jitterbug music with names like "Gut-Bucket Gus" and "Jane Shakes Her Hair" that suited the music to a T.

Sackson and Pommers, who in their distinguished and portly elegance looked anything but jitterbug types, launched this set with great straight-faced gusto. Pommers looks imperturbable on the piano bench, but his fingers danced through this music and his syncopations were as cool as any jazz musician's. Sackson followed suit, sliding and bouncing around his instrument with the style of a country fiddler.

Surprisingly, it was in the more formal pieces by Carpenter and Cowell that the performances were not all they could have been. Sackson had a hard time getting warmed up, and the expansive lines of the Carpenter were not ideal warmup exercises. The pitch was not reliable here and precision seemed to take a back seat to warmth of tone. In the Cowell Suite, it was Sackson's wide vibrato that made the pitch ambiguous and gave the lines more weight than they could comfortably sustain.

The ensemble throughout the evening was exemplary, however, and the music was well worth hearing.