In 1945 four young players formed a string quartet called the Moscow Conservatoire Quartet . Mstislav Rostropovich was the cellist , Rostislav Dubinsky and Nina Barshai played the violins and Rudolf Barshai played the viola . The group originally came together in 1945 as the Moscow Conservatoire Quartet with Mstislav Rostropovich on cello , Rostislav Dubinsky and Nina Barshai on first and second violins and Rudolf Barshai on viola , all members of a class taken by Mikhail Terian , the viola player of the Comitas Quartet .