Violinist Denes Zsigmondy and his wife, pianist Anneliese Nissen, proved faithful servants of Bartok's fertile genius in a program at the National Gallery Sunday night. Honoring the 100th anniversary of the composer's birth, they chose three of his most demanding works -- the first two piano and violin Sonatas from the early '20s and the Sonata for solo violin of 1944, his last completed work.

The sheer density of ideas in the two duo sonatas requires intense concentration from both performers and listeners. Coming toward the end of the period when Bartok was still defining his own voice, the music shifts character frequently, mixing references to almost every major force from atonaltiy to impressionism with large doses of material inspired by folk sources. Zsigmondy, a native of Hungary now resident in this country, and Nissen have played these works over many years, and they approached them with the ease born of experience. Though more brilliance would have sharpened the impact of their interpretation, its continuity was expertly sustained as the piano and violin, following Bartok's dictates, moved along fiercely independent paths.

The solo Sonata is one of Bartok's most profound utterances. Zsigmondy lacked the control, particularly in the transcendent song of the third movement, to realize the deepest intent of the music, but he approached its fierce challenges with informed sensitivity.