“After a three-year exile on the city’s outskirts, the famed opera company is returning to its renovated 18th Century theater in the heart of Milan in time for its traditional Dec. 7 opening night. The contested renovation was completed a few weeks ahead of schedule, giving conductor Riccardo Muti time for rehearsals. Muti tested acoustics of the “new” La Scala with a 40-minute rehearsal last Friday, and theater officials reported that the maestro broke into applause at the end to express his satisfaction with the sound quality.”