Reprinted from yesterday's late editions

Taking liberties with the tempo in Bach's music is a risky business. A performer can do it, provided he first establishes a strong, even pulse against which the tempo deviations can push.

In his all-Bach program at the National Gallery Sunday night harpsichordist Ralph Hill demonstrated that he is a sensitive musician, responsive to the expressive rise and fall of lines in Bach's polyphony. Unfortunately, this same sensitivity led to some excessive ritards and exaggerated phrasing, particularly in the first half of the program. It was Bach without backbone because the necessary sense of a seemingly inflexible pulse was missing.

Hill is to be commended for putting together an exceptionally interesting program which included some of the less-frequently played Bach works. Of note was a late Bach work, the "Prelude, Fugue and Allegro in E-flat Major," which, according to Bach's indication on the original manuscript, was to be played by either harpsichord or lute. Hill's performance, making effective use of the lute stops, was excellent, as was his playing of the "Fantasie in C minor" with its frequent hand-crossings. Throughout, he made good use of the sound resources of the harpsichord, giving a greater sense of variety than one usually associates with the instrument.