Bring up Golden Age Hollywood filmmaker Busby Berkeley, and most people conjure his staging of elaborate, kaleidoscopic dance numbers in such films as “Dames” and “Footlight Parade,” Ginger Rogers singing “We’re in the Money” at the height of the Depression in “Gold Diggers of 1933,” or his sinuous camera weaving through dancer’s legs in such hits as Oscar-nominated “42nd Street” (1933). A three-time Oscar nominee (for Best Dance Direction), Berkeley’s musicals were credited with saving Warner Bros.