Just exactly how an American pianist of such enormous distinction as David Lively, who performed last night at the Kennedy Center's Terrace Theater, can be well known in Europe but a virtual stranger in his own country is a mystery -- and a perplexing one.

A resident of Paris, he was spotted there by pianist Eugene Istomin. Last night, Istomin joined Lively in a two-piano encore that inaugurated a new $39,000 Steinway given to the center by Bell Atlantic. Istomin said earlier he doubts that Lively has given more than "two or three" full-fledged recitals in his native land.

He is so impressive a pianist that one hardly knows where to start.

The most obvious thing is to focus on his enormous physical power and precision, shown most spectacularly in the furious pyrotechnics of Stravinsky's piano transcription of three movements from "Petrushka," with sensationally played bass runs in the "Danse russe" and marvelously clean rhythms and huge sonorites in "La Semaine grasse." The regular piano in the Terrace Theater has the kind of quick, clear action that will do justice to a technique as fine as Lively's.

But arguably the loveliest moment of the evening was the one that challenged Lively's digital dexterity the least, an encore performance of the great Gershwin blues Prelude, played simply rapturously -- with superbly judged bending of the lines and exceptional tonal and dynamic control.

There was also a beautifully quiet "Clair de lune" in Debussy's "Suite bergamasque." For years overplayed, "Clair de lune" then sort of fell out of the concert repertory, and it was a pleasure to hear it again.

Schumann's "Novelettes," Op. 21, were splendidly fluent, with a clear command of the dense complex Schumann piano textures. And the Third Beethoven Sonata in C major, Op. 2, was admirably forthright.

For a second delightful encore, the new piano was rolled on stage, with Lively playing the treble of Schubert's "Marches militaires" on it while Istomin handled the bass on the other instrument.