Remember Sisyphus, rolling his rock up the hills of Hell again and again? Mieczysław Weinberg, a symphonist of stature, wrote seven operas. Despite high praise from Dmitri Shostakovich, only the sixth seems to have seen the stage in Weinberg’s lifetime. Yet his first, The Passenger, concerning a shadowy survivor of the concentration camps, won international acclaim at its posthumous unveiling in Bregenz, Austria, in 2010, and other productions followed. In 2013, the German city of Mannheim took a flyer on Weinberg’s last opera, The Idiot, after that oddball novel in which Dostoevsky challenged himself to conjure up a protagonist truly good, guileless, and pure of heart. And here he is at last, Dostoevsky’s saintly Prince Myshkin by way of Weinberg, taking his place on the stage of the Bolshoi. —M.G.