I'm not sure why you would assume they violate code except to be dramatic. Concerts have been held in industrial places in secret, but if you hear about one it's typically above board.

And yet the original parent said:

the best part of Detroit is a trend of extremely creative people being able to do whatever they want with their respective spaces

Or did I misunderstand, and they are allowed to do anything zoning-wise but are still held to the appropriate codes.