Pianist Peter Taka'cs turned to the audience Saturday night before performing the Sonata No. 3 (1965) by Roger Sessions and gave a mini-lecture on the structure and meaning of the piece complete with illustrations of its basic tone row and the various ways it is used. This sort of discussion should happen more often, at least when the performer is as intelligent and articulate as Taka'cs and the music is as challenging as the Sessions Sonata.

It was anything but academic, particularly when he reached the sonata's "beautiful, moving, very painful" third movement -- a memorial to John F. Kennedy with three harsh sforzandos at a climactic point representing the three gunshots that killed him. And it made the lucid, passionate performance that followed much easier to enjoy.

The Sessions was the highlight of a brilliantly played program that also included Beethoven's E-flat Sonata, Op. 27 No. 1, a Nocturne and Scherzo by Chopin, Scriabin's "Black Mass" Sonata and Ravel's "Valses Nobles et Sentimentales." The interpretations focused largely on structure, without neglecting all of the music's other values, and he was particularly illuminating in the Scriabin, whose structures often seem problematic in performance. His Ravel -- a study in the stretching and compression of rhythms, the calculated displacement of accents, gradations of tonal color and the creative uses of silence -- was particularly dazzling.