Occupying a converted 1920s warehouse in the trendy Gulch area, City Hall Entertainment Space has quickly become the hot spot for mid-level touring acts that can pull in 1,000 to 1,500 people: rock, rap, soul or pop. It’s a spacious venue with good sight lines, a well-stocked bar with local brews, and very nice restrooms — complete with attendants. Lines snake around the block for popular shows. With the original building gutted up to the steel-beam rafters, City Hall Entertainment Space is a wide-open, neo-industrial space with plenty of elbow room, even for sold-out shows.