Performers take the curtain call after the performance at Vienna State Opera House, in Vienna, Austria, May 25, 2019. Vienna State Opera House held a special program on Saturday to pay tribute to the 150th anniversary of the house and its artists. The Vienna State Opera House is one of the most famous opera houses in the world which was opened on May 25, 1869. (Xinhua/Guo Chen)

Audience wait for the performance to start at the Vienna State Opera House, in Vienna, Austria, May 25, 2019. Vienna State Opera House held a special program on Saturday to pay tribute to the 150th anniversary of the house and its artists. The Vienna State Opera House is one of the most famous opera houses in the world which was opened on May 25, 1869. (Xinhua/Guo Chen)

Audience wait for the performance to start at the Vienna State Opera House, in Vienna, Austria, May 25, 2019. Vienna State Opera House held a special program on Saturday to pay tribute to the 150th anniversary of the house and its artists. The Vienna State Opera House is one of the most famous opera houses in the world which was opened on May 25, 1869. (Xinhua/Guo Chen)

Photo taken on May 25, 2019 shows the exterior of Vienna State Opera House, in Vienna, Austria. Vienna State Opera House held a special program on Saturday to pay tribute to the 150th anniversary of the house and its artists. The Vienna State Opera House is one of the most famous opera houses in the world which was opened on May 25, 1869. (Xinhua/Guo Chen)

Photo taken on May 25, 2019 shows the exterior of Vienna State Opera House, in Vienna, Austria. Vienna State Opera House held a special program on Saturday to pay tribute to the 150th anniversary of the house and its artists. The Vienna State Opera House is one of the most famous opera houses in the world which was opened on May 25, 1869. (Xinhua/Guo Chen)

Photo taken on May 25, 2019 shows the exterior of Vienna State Opera House, in Vienna, Austria. Vienna State Opera House held a special program on Saturday to pay tribute to the 150th anniversary of the house and its artists. The Vienna State Opera House is one of the most famous opera houses in the world which was opened on May 25, 1869. (Xinhua/Guo Chen)

Photo taken on May 25, 2019 shows the interior of Vienna State Opera House, in Vienna, Austria. Vienna State Opera House held a special program on Saturday to pay tribute to the 150th anniversary of the house and its artists. The Vienna State Opera House is one of the most famous opera houses in the world which was opened on May 25, 1869. (Xinhua/Guo Chen)