After the cancelation of events across the country in wake of Tuesday's terrorist attacks on New York and Washington, D.C., performing-arts organizations are making determined efforts to resume their schedules. Both the San Francisco Opera and the San Francisco Symphony will have their scheduled performances Wednesday evening. SFO general manager Pamela Rosenberg is planning to make brief pre-curtain remarks and to ask for a minute of silence, and so also, according to reports, Michael Tilson Thomas plans to address the audience before the Symphony's performance of Mahler's Sixth Symphony. San Francisco Performances and Cal Performances will produce their programs on schedule. In Los Angeles, where Kent Nagano was to make his conducting debut on Wednesday, September 12, leading the Los Angeles Opera's premiere of a new production of "Lohengrin," the performance was postponed to Sept. 15, in observation of the tragic East Coast events and also because Nagano - flying from Berlin to LA on Tuesday - got stuck in Frankfurt when his plane was diverted and the air system was shut down. Even if Nagano makes it to LA on Thursday (still a question), his scheduled rehearsals with the Berkeley Symphony will have to be rearranged, under the direction of George Thomson or Alasdair Neale, as colleagues are coming to each other's help. Instead of the Sept. 12 "Lohengrin," LA Opera will add a performance, possibly on Oct. 1. Janos Gereben/SF [log in to unmask]