The free event, the third annual Concert for Europe, was scheduled to take place outside the city's Sch‹nbrunn Palace on June 2, but a rainstorm forced its postponement. Organizers vowed to reschedule it before July 1, when Austria gives up the rotating presidency of the European Union, but that seemed a daunting task given the schedules of the participants, which are usually set years in advance.

"Everyone thought it was impossible," an announcement on the event's web site said. "We've done it!"

The hurried negotiations that made the new date possible involved the President and the Chancellor of Austria, the Austrian Post Authority, the Austrian Central Bank, the national broadcaster ORF and the electric utility Verbund, as well as Domingo and the Philharmonic.

It is not clear whether tenor Rolando Villaz‹n, who was scheduled to appear on June 2, will be making an appearance. The web site lists a "special guest" but makes no mention of Villaz‹n.

The program includes works by Shostakovich, Schumann, Rossini, Mozart and others.

The concert is expected to draw a crowd of more than 90,000, and it will be broadcast live on ORF and across Europe.