When someone once asked Bach the secret of his stunning keyboard technique, J.S. replied that all one had to do was to see that the right notes were produced in the right time and the instrument played itself. Harpsichordist Trevor Pinnock is of the same school. His technique is so reliable that, when performing, he needs to think only of the music, and it almost does seem that the instrument plays itself.

At the University of Maryland's Adult Education Center last night, Pinnock played a timely program of music by Bach, Handel and Scarlatti that was full of contrasts. The opening Handel G Major Chaconne, improvisatory in nature and virtuosic in idiom, does not do full justice to that composer's genius, but then Handel was a master of song, not of the keyboard. The Bach arrangement of a D Major Vivaldi Violin Concerto was composed as an exercise when Bach was young, and its solutions to the problem of adapting solo violin and orchestra to the harpsichord are, in many respects, more interesting than the music itself.

This was followed, however, by two supreme examples of Bach's art, Partitas Nos. 1 and 2, which are full of the inventiveness and the appeal to the senses that characterize Bach at his best. The program ended with three Sonatas in D Major by Scarlatti. Scarlatti himself referred to these sonatas as "exercises," and with all their ornateness and echoes of Spanish folk idiom (Scarlatti spent most of his career in Madrid), they each pose special technical challenges to the performer.

Pinnock seemed in his element with all this. His playing is characterized by a marvelously physical sense of movement, a feeling of inevitability and direction, and,though he doesn't dwell much on the conventions that address the affective in the music, he certainly does infuse everything he touches with vitality.