SOCIAL CALENDAR.(CAPITAL REGION)(Calendar)

MUSIC AND THEATER ARGERICH AND ALEXANDER GURNING. Performing Bartok's Sonata for two pianos and percussion; and Borodin's String quartet No. 2 in D Major. 8:15 p.m. Tuesday. Spa Little Theatre, Saratoga Performing Arts Center, Saratoga State Park, Saratoga Springs. 587-4427. $27.50-$32.50.

SARATOGA CHAMBER MUSIC FESTIVAL: NIKOLAJ ZNAIDER. Performing Tchaikovsky's ``Souevenirs de Florence''; Glinka's ``Trio Pathetique''; and Shostakovich's Four Waltzes for flute, clarinet and piano. 2:15 p.m. Today. Spa Little Theatre, Saratoga Performing Arts Center, Saratoga State Park, Saratoga Springs. 587-4427. $27.50-$32.50.

WARREN VACHE. The trumpeter performs with …