Stephanie Brown, the first pianist to be awarded the prize named in memory of the late, great Brazilian pianist Guiomar Novaes, played a recital yesterday afternoon in the Kennedy Center's Terrace Theater.

Though her program was originally to have opened with the C-major Sonata, K. 330, of Mozart, Brown chose substitute the Beethoven Sonata, Op. 110. It must be said that the Beethoven was strangely unsettled most of the time. There was some attractive playing in the slow movement but not the total repose or control required in the dramatic pages.

One disturbing element in the Beethoven reappeared in the succeeding "Tombeau de Couperin" by Ravel: in playing softly, Brown fails to undergird her tone with a kind of muscle or fiber that is needed no matter how quiet the sound. Much of the Ravel was tinged with delicate beauty, but it lacked both sufficient variety and the immense power to put the Toccata over the top.

There were no problems in two pieces by Villa-Lobos, a Brazilian dance and the Choros No. 5, for which the artist supplied all the needed flashy sound.

Brahms' Opus 1 Sonata is taxing for any pianist. It proved to be Brown's most successful venture. She had its arduous demands thoroughly under her fingers and, where Brahms permitted it, she supplied lyric poetry.