The National Symphony Orchestra's Beethoven Festival continued Saturday with a gorgeous performance of the Concerto No. 1 in C Major, Op. 15, by pianist Lilian Kallir under the direction of Gerard Schwarz. The bright evening also included the rarely heard overture to "King Stephen," Op. 117, and the Symphony No. 6 in F Major, Op. 68.

Chronologically Beethoven's second, but his first in order of publication, the Op. 15 concerto begins in the world of Mozart and transcends it almost immediately. Even at its most formal the work exudes the air of freedom, with the seamless song of its middle movement and the profound satisfaction of its bouncy finale. The beautiful NSO strings had never been as articulate as they were for Schwarz in the opening of the concerto. And from Kallir's entrance it was clear that this was to be a reading of inevitability and grace, with the first note logically and gently leading to the last in the course of a lovely summer voyage.

The orchestral tempos tended toward the fast throughout the evening, but in the largo they were perfect. The wind section was serene and lovely. The conductor seemed to breathe with the soloist as she phrased with discreet and sensuous rubatos just as she had in the first movement's cadenza. If the Steinway tended to clatter rather than sing under pressure, this did not veil the smiles and the strength of the final rondo, and by the close not only the audience but the orchestra as well rewarded Kallir with long applause.

The concert began with the overture to "King Stephen." It is a shiny little jewel, foreshadowing the later setting of Schiller's "Ode to Joy" without its depth or melancholy. The playing was exquisite.

The second half of the program was given to the "Pastoral" Symphony No. 6. There was a Haydnesque regularity to the heartbeat of the score, and in the flute's nightingale and the clarinet's cuckoo it was steady as a clock. But the playing was admirable. Schwarz places a high value on clarity and tonal beauty, and his precise baton manner made his intentions as clear as a mountain brook.