To write about Rudolf Serkin playing three Beethoven sonatas, one from each of the composer's major creative periods, is a task that can be accomplished in a single paragraph or an entire book.

Yesterday afternoon in the Kennedy Center, the great musician played the first of the 32 piano sonatas, the 23d of them, called the "Appassionata," and the 29th, known as the "Hammerklavier." As these works take in the composer's lifetime, so does their performance by Serkin embody a life-long study, the results of which have given him a total awareness of their meaning, particular insights into the significance of each note and phrase, and the power to project their minute implications and total entitles.

Serkin made the concert an occsion of ideal articulation, immaculate in its varied scale, and lacking any suggestion of excess, and this in music that often tempts others to exaggerated heights.

As Beethoven increased his demands on the developing piano, so did Serkin as he moved from the brilliant designs of the opening sonata to the epic struggles of the fugue that closes the "Hammerklavier," the slow movement of which he fittingly made the crown of the afternoon. Beethoven's music was fully revealed, ideally served.