What of the pre-revolutions composers like Mussorgsky, Glinka and Rimsky-Korsakov was allowed? Considering that this was bourgeois art, often full of religious symbolism and allegory. Surely that was something that the Bolsheviks would be against. Were any operas banned? were performers and conductors censured?
Please define time range. In pre-Soviet Union times (i.e. before 1922) there was a several bans on 'bourgeois art'.
Lately most of the pre-revolution production (the ones that didn't praise Tsar, aristocracy or exploitators) was allowed to play on stages.
Of course, there was a number of 'bans' during the mass killings of 1937-1938 but they mostly related to conductors and performers declared 'Enemy of the State', not because they performed pre-revolution pieces.