Through clever programming, Miles Hoffman, artistic director of the Library of Congress's Summer Chamber Music Festival, gave the audience at the Coolidge Auditorium a little bit of everything last night and consequently left everyone happy. Even more to his credit, he did so without ever putting more than two performers on the stage at the same time.

The first and least-well-played work on the program was Robert Schumann's Adagio and Allegro for Horn and Piano, Op. 70, played here by Anthony Cecere and pianist Edmund Battersby. Battersby did fine, crafting the notes gently in the "Langsam" and with spirit in the "Rasch und feurig." But Cecere appeared to have problems from the start. It's not that he fluffed a note or two -- any horn player on the best of days might do the same -- but from the very start it seemed his heart just wasn't in the music. He languished in the first part and sounded brittle in the second.

The same can hardly be said for violinist Paula Francis and pianist Jean-Louis Haguenauer, both of whom played Lee Hoiby's Serenade for Violin and Piano, Op. 44 (1986-90), with vivid conviction and irrepressible musicianship. Strains of Prokofiev and Poulenc make the Hoiby work sound a little curious on first listening, but the freshness of melodic and harmonic invention is irrefutable, and the gentle, ebbing quality of the opening combined with the drama of the transition makes one want to hear more. Francis's playing was especially memorable: effective, yet always slightly understated.

Hoffman's decision to abut this work against Shostakovich's Sonata for Viola and Piano, Op. 147, was a good idea made even more agreeable by the fact that Hoffman himself was the violist. Compared with the lyric energy of the Hoiby composition, this Sonata has all the outward warmth of the winter sun: There is an austerity here, closer to coolness than frugality. Yet Hoffman and pianist Ann Schein should be commended, not only for bringing the dancelike Allegretto to life (which was easy) but for finding vivacity in the two outer movements (which was not).

The program ended with splendid, crowd-pleasing music for four hands and two pianos played by Battersby and Haguenauer. Faure's "Dolly" Suite, Op. 56, for four hands was an absolute delight and Brahms's "Variations on a Theme of Haydn," for two pianos, Op. 56b, was equally impressive. One rarely hears solo pianists -- even as good as these -- play together as seamlessly.