Mondays and Wednesdays are loud at the vast Boeing factory in Everett, Washington. As the Machinists’ contract campaign heats up, the workforce has been serenading management at lunch with air horns, train horns, and vuvuzelas—plus chants of “Out the Door in ’24.” Forty miles south, in Renton, where workers construct the moneymaking 737, second shift workers have used their meal breaks to blast Bluetooth speakers at top volume with ’90s rap, death metal, ’80s pop, and opera—all simultaneously, said Jon Voss, a 13-year mechanic in the wings building.