Name and describe the first silent film. in what year was sound added to films?

Vitaphone, as this system was now called, was publicly introduced on August 6, 1926, with the premiere of the nearly three-hour-long Don Juan; the first feature-length movie to employ a synchronized sound system of any type throughout, its soundtrack contained a musical score and added sound effects, but no recorded 

,mhngcbfvdsxdfgrthjk,jmhgfds