People attend the Summer Night Concert (Sommernachtskonzert) at the Schoenbrunn Palace in Vienna, Austria, June 20, 2019. The Summer Night Concert 2019 was staged at the world heritage site of Schonbrunn Palace in Vienna on Thursday. The annual concert was performed by Vienna Philharmonic Orchestra and free for audience. (Photos: Xinhua)

People attend the Summer Night Concert (Sommernachtskonzert) at the Schoenbrunn Palace in Vienna, Austria, June 20, 2019. The Summer Night Concert 2019 was staged at the world heritage site of Schonbrunn Palace in Vienna on Thursday. The annual concert was performed by Vienna Philharmonic Orchestra and free for audience.

People attend the Summer Night Concert (Sommernachtskonzert) at the Schoenbrunn Palace in Vienna, Austria, June 20, 2019. The Summer Night Concert 2019 was staged at the world heritage site of Schonbrunn Palace in Vienna on Thursday. The annual concert was performed by Vienna Philharmonic Orchestra and free for audience.

People attend the Summer Night Concert (Sommernachtskonzert) at the Schoenbrunn Palace in Vienna, Austria, June 20, 2019. The Summer Night Concert 2019 was staged at the world heritage site of Schonbrunn Palace in Vienna on Thursday. The annual concert was performed by Vienna Philharmonic Orchestra and free for audience.

People attend the Summer Night Concert (Sommernachtskonzert) at the Schoenbrunn Palace in Vienna, Austria, June 20, 2019. The Summer Night Concert 2019 was staged at the world heritage site of Schonbrunn Palace in Vienna on Thursday. The annual concert was performed by Vienna Philharmonic Orchestra and free for audience.

Chinese pianist Wang Yujia (1st L) performs on stage during the Summer Night Concert (Sommernachtskonzert) at the Schoenbrunn Palace in Vienna, Austria, June 20, 2019. The Summer Night Concert 2019 was staged at the world heritage site of Schonbrunn Palace in Vienna on Thursday. The annual concert was performed by Vienna Philharmonic Orchestra and free for audience.

People attend the Summer Night Concert (Sommernachtskonzert) at the Schoenbrunn Palace in Vienna, Austria, June 20, 2019. The Summer Night Concert 2019 was staged at the world heritage site of Schonbrunn Palace in Vienna on Thursday. The annual concert was performed by Vienna Philharmonic Orchestra and free for audience.

People attend the Summer Night Concert (Sommernachtskonzert) at the Schoenbrunn Palace in Vienna, Austria, June 20, 2019. The Summer Night Concert 2019 was staged at the world heritage site of Schonbrunn Palace in Vienna on Thursday. The annual concert was performed by Vienna Philharmonic Orchestra and free for audience.

The Vienna Philharmonic Orchestra (Wiener Philharmoniker) performs during the Summer Night Concert (Sommernachtskonzert) at the Schoenbrunn Palace in Vienna, Austria, June 20, 2019. The Summer Night Concert 2019 was staged at the world heritage site of Schonbrunn Palace in Vienna on Thursday. The annual concert was performed by Vienna Philharmonic Orchestra and free for audience.

People attend the Summer Night Concert (Sommernachtskonzert) at the Schoenbrunn Palace in Vienna, Austria, June 20, 2019. The Summer Night Concert 2019 was staged at the world heritage site of Schonbrunn Palace in Vienna on Thursday. The annual concert was performed by Vienna Philharmonic Orchestra and free for audience.