Industrial music is amazing. Think of it: Back in the ’80s, a bunch of fucking psychos were like, “Maybe we could make something that’s thrash metal but also disco,” and then the whole world changed. I know that’s not really how it went. I know that’s not what Cabaret Voltaire or Throbbing Gristle or Einstürzende Neubauten had in mind. I know that you could come up with all sorts of reasons why Nine Inch Nails, the subject of this particular concert review, aren’t really industrial music at all. But when NIN’s Peel It Back tour came to Baltimore on Tuesday, that’s how it felt — as if the entire histories of KMFDM and Skinny Puppy and Front 242 unfolded to take us to the point where 60-year-old Trent Reznor could punctuate his electro ooze-throb with jagged guitar eruptions and make a whole arena levitate.