Marilyn Horne sings superbly almost anything she chooses, from Beethoven's "Die Ehre Gottes aus der Natur," which opened her program Saturday night in the Kennedy Center Concert Hall, to "Jeanie with the Light Brown Hair," which was the final encore. Her voice is unique in range, power and agility, and she uses it with an intelligence that has kept it in amazing condition. She begins fully warmed-up and her voice seems to improve throughout a program.

She has a versatility far beyond such bel canto singers as Sutherland and Pavarotti; she is obviously proud of that versatility, and rightly so. Half of her lengthy program was devoted to lieder by Beethoven, Schumann and Brahms, and the performance was impressive, even when the tone took on, momentarily, a slightly raw edge; even when her leaps from one register to another made a song sound, inappropriately, like a dialogue between high and low voices.

But although she does many things well, she does not do everything equally well. The German lied is a highly specialized art, requiring years of total immersion before a singer can master all its nuances. For all her vocal strength and opulence, Horne has not undergone that immersion; she lacks the special sensitivity to the overtones of German words that characterizes lieder singing at its best, and in this repertoire she cannot compensate through pure vocal ability. The simple fact is that most lieder do not require anywhere near the vocal resources she has at her disposal. Aware of these limitations, she wisely chose songs that respond well to her organ-like tonal range and special gift for dramatic projection. The three groups were arranged intelligently, each rising to a fine climax at the end. But she could have proved her point with a single group (preferably the one by Schumann), saving more time and energy for the bel canto repertoire that her fans obviously came to hear.

That came in the second half, which was devoted entirely to little-known works by Rossini: juvenilia, music of his later years, and a stunning little cantata, "Giovanna d'Arco," which portrays Joan of Arc about to set off on her military career. The music was as spectacular as the subject, the performance was breathtaking, and all of it was true recital material, composed for voice and piano, not transplanted operatic music. Pianist Martin Katz contributed significantly to a very impressive program.