Pianist Janice Weber came to the National Gallery's East Garden Court last night armed with an awesome degree of dexterity, unshakeable concentration and a delightful way with a rubato. Since the bulk of her program was all six movements of Grandados' "Goyescas," these pianistic and artistic virtues were thoroughly tested.

These are six big pieces, written by a composer who reveled in a chauvinistic romanticism and a virtuosic command of pianistic color. To play them effectively requires a certain degree of abandon and a truely expansive imagination. It also requires extraordinary technical facility. Weber had all of this in abundance. She maintained a nice balance between spontaneity and control, between subjective expression and objective structure.

There were things that might have been better. She might have used a stronger left hand in the Fandango. There might have been a little more contrast between the pieces, and a more heightened sense of inevitability at the very end. But these are minor quibbles about a performance that, as a whole, was impressive.

A pleasant Prelude and Fugue by Shostakovich opened the concert. It built up to a furious storm of notes, but, in company with the Granados that was to come, it sounded almost restrained.