Reese Witherspoon, Scarlett Johansson to do animated comedy

Los Angeles: Reese Witherspoon, Seth MacFarlane and Scarlett Johansson have joined Matthew McConaughey as voice actors in the animated comedy 'Sing'.

Taron Egerton and Tori Kelly also star in 'Sing', which will be released on December 21, 2016, reports variety.com.

McConaughey will play a koala who presides over a once-grand theatre that has fallen on hard times. He decides to regain the glory by producing the world's greatest singing competition.

Contestants are a mouse (MacFarlane), a timid teenage elephant (Kelly) with a case of stage fright, an overtaxed mother (Witherspoon) tending a litter of 25 piglets, a young gangster gorilla (Egerton) and a punk-rock porcupine (Johansson) struggling.

The film features more than 85 songs and is directed by Garth Jennings from his own script. Producers are Chris Meledandri and Janet Healy.