Even if you can 't be there for an opera ( opening with a gala to end all galas every sacrosect December 7 ) , attend a concert or dance performance there or at least visit the little museum ( left of the theater ) , if only for a chance to see a strand of Mozart 's hair , Toscanini 's baton , or a peak into the sumptuous Neoclassical auditorium with its six tiers of balconies and galleries .
It is worth visiting any form of performance there .