Scarlett Johansson (Lucy) and Reese Witherspoon (Wild) have joined the stage for the animated musical Sing from director Garth Jennings (The Hitchhiker’s Guide to the Galaxy).

The pair will join Matthew McConaughey (Gold), John C. Reilly (Chicago) and Taron Egerton (Kingsman: The Secret Service) in the film that follows theater owner Buster Moon (McConaughey), a Koala who is looking to revive his business by producing a singing competition. The five contestants include a crooning mouse (Seth MacFarlane, Ted 2), a timid teenage elephant (singer Tori Kelly), a gangster gorilla (Egerton), an overworked mother (Witherspoon) and a punk-oriented porcupine (Johansson).

The film’s soundtrack will reportedly include more than 85 hit songs and is set to release December 21, 2016. The film is one of three future releases for Universal and Illumination Entertainment that include the upcoming The Secret Lives of Pets. The companies are most famous for pairing up to make the Despicable Me films as well as its spinoff, Minions.

Despite having experience as a singer, Johansson has never starred in  a musical and her only animated film credit was in 2004’s The SpongeBob SquarePants Movie. She is also lending her voice as the snake Kaa in Disney’s live-action remake of The Jungle Book. Witherspoon won an Oscar for playing June Carter Cash in the music biopic Walk the Line. She also voiced the lead character in the sci-fi adventure Monsters vs. Aliens. Witherspoon will be seen next when she reteams with Alexander Payne (Election) for the comedy Downsizing.

We’ll have more on Sing as more information becomes available.