Compared to the relatively steady spread of vocal music instruction, instrumental music was slow to take its place in the school curriculum. Orchestras, based on community models, and bands, based on military band models, entered the schools in mass beginning in the first decades of the twentieth century. By the beginning of World War II, spurred on by instrument manufacturers, contests, and athletics, bands were found in most American high schools and orchestras were in many schools as well, mainly in larger cities.