In the Renaissance people who went to the theatre, stayed stand up, and there wasn't the roof, so the audience was in the open air.
All social classes shame the same room, cause they could just stay in the pit.
Nowadays instead you can change the seat where sit down. If you pay a lot you can stay in the pit or you can stay in the gallery.
In the Renaissance performances were about Greek themes and there were for a refined audiences. There were a lots of genres of theatre, like today; for example comedy, satirical, tragedy ecc..
Today every body could go to the theatre and see what they want.