Singers perform during dress rehearsal of opera Bluebeard's Castle in Budapest, Hungary

Singers of Hungarian State Opera House perform during a dress rehearsal of Hungarian composer Bela Bartok's one-act opera Bluebeard's Castle in Budapest, Hungary, on May 23, 2018. The premiere of the new production of Bluebeard's Castle will be staged in Erkel Theatre in Budapest on May 24. (Xinhua/Attila Volgyi)