The support group for opera addicts is in session, and its participants perform Prokofiev’s Betrothal in a Monastery. Rarely performed outside Russia, and consigned to oblivion by Andrei Zhdanov’s anti-formalist policies after the Second World War, the work is transformed by Dmitri Tcherniakov’s extravagant staging. Under the baton of Daniel Barenboim, an all-star cast featuring Aida Garifullina and Violeta Urmana bring the characters to life on stage at Berlin’s Staatsoper Unter den Linden.