An event begins long before anybody arrives. Somewhere a contract is signed, a ballroom is booked, a field is measured, a road closure is discussed, a caterer is asked whether 800 meals can become 950, and somebody opens a spreadsheet containing timings that will eventually determine when hundreds of other people move. Then, on the appointed morning, the doors open and the machinery is expected to disappear. The guest should see the wedding, conference, basketball game, music