The London FT reported as follows on the recent Tosca performances:

   Scarpia's entrance, which should be one of the most hair-raising
   moments in all opera, was completely muffed.  Extras entering at
   various points through the stalls made it unclear where Scarpia was
   actually meant to be.  Nor did it help that the RAH staff chose that
   moment to let in the latecomers, so that the posse of evil henchmen
   seemed to include rather a lot of smart-suited City workers and their
   lady friends.

What a touch of genius.

John G. Deacon
Campobello, Javea: http://www.holidayhome.co.uk/deacon.html