The Vienna Philharmonic Orchestra performs during the Summer Night Concert at the Schoenbrunn Palace in Vienna, Austria, Sept. 18, 2020. The Summer Night Concert 2020 was staged on Friday by the Vienna Philharmonic Orchestra at the Schonbrunn Palace, a world heritage site in Vienna. The seat capacity this year has been greatly reduced due to COVID-19.Photo:Xinhua

The Vienna Philharmonic Orchestra performs during the Summer Night Concert at the Schoenbrunn Palace in Vienna, Austria, Sept. 18, 2020. The Summer Night Concert 2020 was staged on Friday by the Vienna Philharmonic Orchestra at the Schonbrunn Palace, a world heritage site in Vienna. The seat capacity this year has been greatly reduced due to COVID-19. Photo:Xinhua

The Vienna Philharmonic Orchestra performs during the Summer Night Concert at the Schoenbrunn Palace in Vienna, Austria, Sept. 18, 2020. The Summer Night Concert 2020 was staged on Friday by the Vienna Philharmonic Orchestra at the Schonbrunn Palace, a world heritage site in Vienna. The seat capacity this year has been greatly reduced due to COVID-19.Photo:Xinhua

The soloist Jonas Kaufmann performs during the Summer Night Concert at the Schoenbrunn Palace in Vienna, Austria, Sept. 18, 2020. The Summer Night Concert 2020 was staged on Friday by the Vienna Philharmonic Orchestra at the Schonbrunn Palace, a world heritage site in Vienna. The seat capacity this year has been greatly reduced due to COVID-19.Photo:Xinhua

The Vienna Philharmonic Orchestra performs during the Summer Night Concert at the Schoenbrunn Palace in Vienna, Austria, Sept. 18, 2020. The Summer Night Concert 2020 was staged on Friday by the Vienna Philharmonic Orchestra at the Schonbrunn Palace, a world heritage site in Vienna. The seat capacity this year has been greatly reduced due to COVID-19. Photo:Xinhua