I spend so much time in the Sydney Opera House Concert Hall and so little time in the Opera Theatre that the sight of this about a week-and-a-half ago caught me by surprise.
As far as I’m aware, there aren’t similar signs in the Concert Hall foyer. This one pictured is on the exterior skin of the Opera Theatre, just before you go up the stairs to the doors for the dress circle.
It struck me as ironic, since there is infinitely more live broadcasting going on from the Concert Hall in any given year than from the Opera Theatre. It reminds me, too, of how the ABC insisted*, during the construction process, on the larger performance space under the western shells being assigned to its activities (i.e. a concert hall for the SSO). In fact, until relatively recently the Concert Hall was known in ABC radio as “Studio 227”.
*The SOH’s history online puts it this way: “At the behest of the Australian Broadcasting Commission (ABC) the NSW
Government changed the proposed larger opera hall into the concert hall
because at the time, [orchestral] concerts, managed by the ABC, were more
popular and drew larger audiences than opera.”