THIS FRIDAY and Saturday, something will happen that has never happened before in public: Anthony Newman will play a piano.

Except for piano, synthesizer and such oddities as the celeste, Newman has performed brilliantly on every keyboard instrument in the book and recorded them for the Newport Classic label, including the complete organ music of Cesar Franck and 23 harpsichord sonatas of Domenico Scarlatti. When he recorded piano music (the complete concertos of Beethoven and, most recently, the complete sonatas of Mozart), he used a fortepiano, the archaic instrument for which this music was written, with a lot fewer keys and a gentler, sometimes more subtly expressive voice than the modern concert grand. His recording of the Beethoven concertos was conducted by Stephen Simon with a New York orchestra using historic instruments.

Newman will return to Beethoven (the Second Piano Concerto) with the same conductor this weekend at the Kennedy Center, but the Handel Festival Orchestra uses modern instruments and Newman will do the same. If he plays a 20th-century piano as well as the 1804 model used in his recordings, it should be a memorable concert.

ANTHONY NEWMAN -- "Mozart: The Complete Sonatas for Fortepiano" (Newport Classic). Appearing at the Kennedy Center Terrace Theater Friday and Saturday evenings and in two children's programs Saturday morning and afternoon.