It's high in theatrical circles (7)
I believe the answer is:
gallery
'high in theatrical circles' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Perhaps you can see an association between them that I can't see?
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for gallery that I've seen before include "Display room" , "Place where pictures are exhibited" , "Passageway; exhibition room" , "exhibition hall" , "eg National, Hayward" .)