Setting the scene
Disney Animation had rebounded with Tangled and Wreck-It Ralph after years in Pixar's shadow, and executives wanted a fairy-tale musical that could rival Broadway's Wicked. Directors Chris Buck and Jennifer Lee reworked Hans Christian Andersen's Snow Queen into a sister story when early tests made Elsa too villainous. Idina Menzel's Broadway pedigree promised vocal power for the ice queen.
What happened
Frozen opened in limited release on November 27, 2013, and went wide, following princesses Anna and Elsa in the kingdom of Arendelle as Elsa's ice powers isolate her and Anna seeks true love. Kristen Bell voiced Anna, Menzel sang Let It Go, and Josh Gad's Olaf supplied comic relief in a snowman who dreams of summer. Robert Lopez and Kristen Anderson-Lopez's songs drove the plot more than traditional side numbers.
Why it still matters
Frozen grossed over $1.2 billion worldwide, became the highest-grossing animated film of its time, and turned Let It Go into a global karaoke staple. It revived Disney princess merchandising and spawned a sequel and Broadway adaptation. Memorable detail: Let It Go was written as Elsa's villain song until the story pivot made it an empowerment anthem, completely changing the character's arc.
Background
Disney revived the animated musical formula for a new generation.