Lynn Harrell's fifth and final encore finally brought the cellist up against a significant limitation last night in the Kennedy Center's Terrace Theater. It was a song transcription--Faure's "Apre s un Re ve" as arranged by Pablo Casals--and the performance made it clear that Harrell's cello cannot pronounce words. There seemed to be little else beyond the instrument's powers in the varied and demanding program Harrell performed with pianist Brooks Smith.

Harrell is built like a professional fullback but can produce nuances of the most delicate subtlety from his instrument: disembodied, high-pitched harmonics; little whispers and rustles of tone; microscopic rushes and hesitations in the tempo; constant, subtle changes in color and dynamics that can endow a musical phrase with vitality.

His hands move with swift, decisive precision, and he hits every note dead center on pitch--except when he chooses not to. That was his choice in his first encore, Chopin's Nocturne in E flat as arranged for cello and piano by David Popper. The double-stopping and other virtuoso effects were very impressive in this performance, but what will be remembered are the little touches of portamento, when the cellist lands his finger near a note and slides into it, giving the music an air of romanticism.

On the program: Chopin's Sonata in G, Op. 65 worked well in a precise, modern-style treatment. Faure''s "Ele'gie" was played with a warmth of tone and exquisite legato phrasing well-calculated to bring out its lyric qualities.

The two greatest works on the program were Ginastera's brilliant, dramatic and technically dazzling "Pampeana" No. 2 and Beethoven's Sonata in A, an impassioned dialogue for cello and piano that is one of his finest chamber works. The cellist's technique seemed as effortless as it was dazzling. His interpretations were solid and thought-out in fine detail.