By Jessica Derschowitz
Updated November 11, 2015 at 04:27 PM EST
Albert L. Ortega/Getty Images

Reese Witherspoon, Scarlett Johansson, and Seth MacFarlane have joined Matthew McConaughey in the voice cast for Illumination Entertainment’s upcoming animated comedy Sing.

John C. Reilly, Taron Egerton, and Tori Kelly will also star in the project from Illumination and Universal. McConaughey will lend his voice to Buster Moon, a dapper Koala who presides over a once-grand theater that has fallen on hard times and stages a singing competition as a final effort to restore the beloved venue to its former glory.

The five leading contenders turn out to be a crooning mouse (MacFarlane), a teenage elephant with stage fright (Kelly), an overtaxed mother (Witherspoon) with a large brood of piglets, a young gangster gorilla (Egerton), and a punk-rock porcupine (Johansson) struggling to shed her arrogant boyfriend.

Sing, which features more than 85 songs, is written and directed by Garth Jennings (The Hitchhiker’s Guide to the Galaxy). It’s scheduled to arrive in theaters on Dec. 21, 2016.