On a Monday in October at 4:30 in the afternoon, the theater at Santa Barbara High School buzzes with half a dozen different constructive activities. And I do mean buzzes — and constructive — as one of the most noticeable things happening onstage is a young man welding. Not 20 feet from where this safety-hooded figure solders pieces of metal, a dance rehearsal with choreographer Christina McCarthy goes on. As the dancers in their sweats practice a combination, the giant tabloid newspapers with headlines about murder and scandal sit suspended overhead; suddenly, things start to make sense. We’re in Chicago — not the Windy City, but the Broadway show, which plays at Santa Barbara High School Theatre November 1-10.