The movie palace was developed as the step beyond the small theaters of the 1900s and 1910s. As motion pictures developed as an art form, theatre infrastructure needed to change. Storefront theatres and nickelodeons catered to the busy work lives and limited budgets of the lower and middle classes. Motion pictures were generally only thought to be for the lower classes at that time as they were simple, short, and cost only five cents to attend. While the middle class regularly began to attend the nickelodeons by the early 1910s the upperclass continued to attend stage theater performances such as opera and big-time vaudeville. However, as more sophisticated, complex, and longer films featuring prominent stage actors were developed, the upperclass desires to attend the movies began to increase and a demand for higher class theaters began to develop. Nickelodeons could not meet this demand as the upperclass feared the moral repercussions of intermingling between women and children with immigrants. There were also real concerns over the physical safety of the nickelodeon theaters themselves as they were often cramped with little ventilation and the nitrate film stock used at the time was extremely flammable.