The 1964 film Mary Poppins featured a modern mix of live-action and animation—and the music was just as revolutionary. Those sing-along numbers that enchanted children delivered deeper messages. Tucked between the fanciful fun of “A Spoonful of Sugar” and the tongue-tangling “Supercalifragilisticexpialidocious” are tunes about feminism (“Sister Suffragette”) and fiscal responsibility (“Fidelity Fiduciary Bank”). Of course, the heart of this soundtrack is everyone’s favorite nanny, and Julie Andrews’ youthful voice is magic. Pair that with Bert’s cockeyed Cockney accent and you get movie musical perfection.