Maria Stuarda ****
By: David Sheward Sondra Radvanovsky in the title role of Donizetti's "Maria Stuarda" A cry of despair arose from the audience at the Metropolitan Opera when the stage manager appeared before the curtain rose on Donizetti's 1835 Maria Stuarda and announced that soprano Sondra Radvanovsky would still be playing the title role but that she had been suffering from a cold. No one need have worried. Thoug…