When composing string quartets, Robert Schumann felt it was important to "avoid symphonic furor and aim rather for a conversational tone in which everyone has something to say." So noted Michael Friedmann, of Yale's School of Music, before an all-Schumann concert on Saturday by the Tokyo String Quartet.

In the quartet's performance at the 92nd Street Y, marking the 150th anniversary of the composer's death, it was a passionate, richly toned discussion among intelligent, charismatic equals: Martin Beaver and Kikuei Ikeda, the violinists; Kazuhide Isomura, the violist; and Clive Greensmith, the cellist.

During the first half of the program the ensemble was joined by Alon Goldstein, a fine young pianist who proved a worthy match for his illustrious colleagues in Schumann's Quartet for Piano and Strings in E flat (Op. 47), written in 1842. This was exemplary chamber music. Its achingly lovely Sostenuto assai contrasted vividly with the electric momentum of the Scherzo, and the lushly melancholic theme of the Andante Cantabile was tenderly played before an impeccably wrought fugue in the final movement.

The program opened with "Märchenbilder" for Viola and Piano (Op. 113). These fairy-tale pictures were written in 1851, three years before Schumann was admitted to the asylum where he died in 1856, suffering from syphilis and tormented by hallucinations. The final movement, the wistful "Langsam," was particularly lovely, with Mr. Isomura's viola singing a dreamy lullaby, and pianist and violist keenly attuned to each other.

The concert concluded with Schumann's String Quartet in A (Op. 41, No. 3), also written in 1842. This was another expressively phrased conversation of burnished grace and vigor -- one the enthusiastic audience seemed thrilled to have overheard.