Artists of China National Opera House perform "Madama Butterfly" by Puccini during the Ljubljana Festival in Ljubljana, Slovenia, on Aug. 23, 2017. (Xinhua/Matic Stojs)

Artists of China National Opera House perform "Madama Butterfly" by Puccini during the Ljubljana Festival in Ljubljana, Slovenia, on Aug. 23, 2017. (Xinhua/Matic Stojs)

Artists of China National Opera House perform "Madama Butterfly" by Puccini during the Ljubljana Festival in Ljubljana, Slovenia, on Aug. 23, 2017. (Xinhua/Matic Stojs)