Jonathan Biss, a 19-year-old pianist from Bloomington, Ind., left a strong first impression last month as soloist in a Beethoven concerto with the National Symphony Orchestra. His playing was introspective, soft-spoken and fresh. These qualities were given three-dimensional shape when he returned Sunday afternoon for a recital at the National Institutes of Health.

He opened his interesting program with Beethoven's quasi-improvisatory Fantasy, Op. 77, an odd work of outbursts and irregular contours that defies a linear approach. Biss didn't so much celebrate the exuberance as tame it. At the keyboard, he sits up straight and keeps his hands mostly flat against the keys, and he draws a pliant, warm tone--linked with an unerring sense of musical good taste.

Schumann's "Kreisleriana" was likewise elegant, with a cool-headed logic that brought forward inner voices. For Schoenberg's freely atonal Six Little Pieces, Op. 19, Biss revealed the best way to convince an audience of the greatness of Schoenberg's music: Play it nicely, lovingly. Biss made these pieces sound like abbreviated Brahms intermezzos.

His reading of Janacek's "From the Street" Sonata held an emotional charge while avoiding weepiness or nostalgia. Yet while his Chopin (Nocturne, Op. 17, No. 2, and Ballade No. 4) benefited from a lovely singing legato line, it wasn't fully formed. Still, there was no hint of a received interpretation.

That Biss is deeply musical, interpretatively principled and technically secure (never ostentatious) makes him an exceptional pianist for any age group. It's unavoidable that the knock of stardom will be heard at his door; let's hope it doesn't interrupt the natural development of this emerging pianist.