Houston is one of only five American cities with permanent professional resident companies in all the major performing arts disciplines: the Houston Grand Opera, the Houston Symphony Orchestra, the Houston Ballet, and The Alley Theatre. Known for the vibrancy of its visual and performing arts, the Houston Theater District—a 17-block area in the heart of Downtown Houston—ranks second in the country in the number of theater seats in a concentrated downtown area, with 12,948 seats for live performances and 1,480 movie seats.