By Jodi Guglielmi
Updated October 26, 2016 10:36 AM
Universal Pictures

Reese Witherspoon wants to be the next big music sensation — or at least, her latest character does.

Witherspoon, 40, is showing off her vocal chops in the upcoming animated film Sing. The actress stars as Rosita, an overtaxed mother who spends her days caring for her litter of 25 piglet children — all while hiding her secret dream of being a singer.

And PEOPLE has an exclusive first look at Witherspoon appearing alongside her character.

“Ever since she was a girl, Rosita has held on to this tiny part of herself she’s been hesitant to share with the world,” Witherspoon tells PEOPLE of her character. “But once she genuinely owns who she is, this shy mom and wife realizes that it would be criminal not to unleash her talents. In fact, it’s the love and passion Rosita’s given and received that pours out of her when she embraces her inner diva and lets loose.”

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In the Illumination Entertainment film, Witherspoon does all of her own singing, taking on Taylor Swift’s “Shake It Off,” Katy Perry’s “Firework” and Bananarama’s “Venus.”

Sing chronicles an adorably furry singing competition, and the star-studded cast also includes Matthew McConaughey, Scarlett Johansson, Taron Edgerton, Leslie Jones, Jennifer Hudson, Nick Offerman and more.

Sing hits theaters Dec. 21.