Riccardo Muti was back at La Scala this past weekend, but don’t get excited. The deposed Milan maestro returned as a guest conductor of the Vienna Philharmonic. “As fans threw long-stemmed white roses onto the stage amid thunderous applause and a chorus of bravos, Mr. Muti – looking solemn but moved – acknowledged the cheers with a nod, placed a single rose on the podium and exited, stage right.”