Members of a chorus from Turkey perform during the opening ceremony of World Choral Expo in Lisbon, capital of Portugal, July 28, 2019. The theme of the five-day event is Voices Meeting for Better World. (Xinhua/Wen Xinnian)

Members of a school chorus from south China's Shenzhen perform during the opening ceremony of World Choral Expo in Lisbon, capital of Portugal, July 28, 2019. The theme of the five-day event is Voices Meeting for Better World. (Xinhua/Wen Xinnian)

Members of A-minor, a chorus from north China's Inner Mongolia Autonomous Region, perform during the opening ceremony of World Choral Expo in Lisbon, capital of Portugal, July 28, 2019. The theme of the five-day event is Voices Meeting for Better World. (Xinhua/Wen Xinnian)

Members of a chorus from Mexico perform during the opening ceremony of World Choral Expo in Lisbon, capital of Portugal, July 28, 2019. The theme of the five-day event is Voices Meeting for Better World. (Xinhua/Wen Xinnian)