When Beyoncé's halftime performance was announced last month, ticket prices and demand for hotel rooms surged exponentially. The streaming event also featured Pentatonix, the a cappella group from Arlington, performing the national anthem. The Texans Mariachi, led by Jose Longoria, revved up the crowd with "El Rey." Mariah Carey appeared via a pretaped performance of "All I Want for Christmas Is You," currently the No. 1 song in the country (again).