We may never know how the music of classical Greece sounded. But that didn't stop early 20th century musical minds from vaulting back to antiquity, perhaps as a delayed reaction to tonality's collapse. Indeed, Stravinsky's Duo Concertante for Violin and Piano, gorgeously rendered Friday night for the Summer Chamber Festival at the Library of Congress's Coolidge Auditorium by violinist Elisabeth Adkins and pianist Ann Schein, evokes a half-real, half-fantasy Golden Age.

Though the dithyramb was rooted in the cult of Dionysis, there is nothing ecstatically ritualistic about the "Dithyrambe" movement closing the duo. Rather, Stravinsky imbues this clean, polished example of modal writing with a relaxed calm. And whereas a lesser musician might have turned all of this flat simplicity into lead, Adkins projected the ideas with a lean, vivid tone.

Walter Piston's Duo for Viola and Cello also follows an eclectic course, albeit within a firmly tonal framework. For violist Miles Hoffman and cellist Cecilia Tsan, the sparing sounds mandated by Piston's use of open strings served as a springboard to a wealth of timbres unheard in most firmly tonal music.

The quality of the Summer Chamber Festival's music making is wildly inconsistent. Though Beethoven's Trio in B-flat for clarinet, cello and piano was given a masterly reading, Schumann's Piano Quartet, Op. 47, was beset by pianist Edmund Battersby's heavy accents and lopsided phrasing. Neither those problems nor Tsan's tuning troubles caused anyone to miss a beat, but thinking beyond the next notes was out of the question.