In her recital at the Kennedy Center last night, soprano Grace Bumbry revealed so many strengths that it seemed unfair to want more. Yet, the nagging feeling persisted that there was more to the songs -- and Bumbry -- than was being given.

Apart from a few harsh sounds in the upper register, Bumbry's voice was as sumptuous as ever, and her ability to color it as masterful as usual. When appropriate she could find the lightest soprano sound, as in a tripping Paisiello gypsy song. For some elegant, sensual DuParc songs her voice throbbed with a veiled voluptuousness. Changes in emotional mood within a song were always carefully matched by shifts in color and pace. Her capacity to shape a phrase dynamically, particularly in the softer end of the scale, was superb.

With so much awareness of the drama of her material one wished that Bumbry had paid more attention to detail. More nuances within a line, more response to the individual words as well as the overall mood would have deepened the expressive effect and perhaps supplied that edge of intensity which was missing from the concert.

Pianist Geoffrey Parsons offered all the help possible by shaping his phrases with the greatest sensitivity, giving Bumbry superb support.