After the Chaos, A New Day for the Cultures Of the Soviet World
Article on cultural vacuum in Russia since fall of Communism decade ago; cultural institutions, trying to survive on shrunken budgets and onslaught of Western mass culture, have taken on commercial partners and dumbed down their offerings in order to attract audiences; some purists view change as threat to great European culture while others view it as welcome liberalization of arts that is challenging and enriching older tradition; photos (M)