I have several scenes that take place in a nightclub. The nightclub was once built as a music hall. I really need the correct wording for parts of the building, inside and outside. I am modelling the setting after this nightclub:- http://www.themiddlesbroughempire.co.uk/index.html
So basically it is an amphitheater. The upper bits that face the stage is/are called balcony(ies). The rest beats me, but that is what I do know. Good luck.
Aye I would've said balcony myself but I thought that it might be a different word being that it's inside, for some reason. I was also looking for details like the columns built against the walls.
I think they would just be support columns for the building. Nothing fancy to call them, unless you like pillars better.
The section of flooring under the balcony would have been called the Parquet area or section. That's pronounced par-kay if you need to know. The half-pillars against the wall are called pilasters.