The Russian chamber orchestra Moscow Virtuosi was put together in 1979, shortly after founder Vladimir Spivakov returned from the Ravinia Festival. At Ravinia, the well-regarded violinist had made an auspicious conducting debut; back in Moscow, heartened by the reception, he became a full-time maestro heading an ensemble of first-chair musicians from various top-rank Russian orchestras. The Soviet government barred the Virtuosi from touring abroad until 1987; these days they are based in Spain and have a thriving international career. On this tour the ensemble has brought along soloist Wendy Warner, a 21-year-old cellist from Wilmette who made her CSO debut as a teenager and just graduated from the Curtis Institute. She'll play the Haydn Cello Concerto in D; Spivakov will play Haydn's delectable Concerto no. 1 for the violin. The remainder of the program consists of Shostakovich's lighthearted Chamber Symphony no. 2, Arvo Part's 1977 Cantus in Memory of Benjamin Britten, and Stalin Cocktail, written by the conservative Russian composer Radian Shchedrin in 1992 far the Virtuosi's 1,000th concert. Sunday, 7.30 PM, Orchestra Hall, 220 S. Michigan; 435-6666.