OVER THE PAST FEW years, Mstislav Rostropovich has been a frequent visitor to Moscow, especially at times of crisis. The former dissident cellist and conductor – who was allowed to emigrate from the Soviet Union in 1974 after the authorities, responding to his vigorous defense of Nobel Prize-winning author Alexander Solzhenitsyn, curtailed his trips to the West – rushed to the Russian capital in August 1991 to oppose the attempted coup against Soviet leader Mikhail Gorbachev. Some two years later, in October 1993, he was back in Moscow when tanks shelled the White House in order to crush opposition to President Boris Yeltsin’s reforms. Throwing his support behind the president, Rostropovich vowed to fight for Russia’s fledgling democracy.