"I was definitely intrigued," says US singer Tori Kelly, on being offered the role of Meena, the vocally blessed but crippling shy elephant in animated feature Sing, from the makers of The Secret Life of Pets, Despicable Me and Minions.

"I had never done anything like this before," she says, at a press tour in Sydney on Monday. "I had always wanted to be in an animated film and be the voice of some awesome character but I never expected it to be this perfect. I couldn't have asked for a better role to play because I relate to her so much."

Sing, out Boxing Day, is a lively and warm-hearted jaunt, skilfully helmed by former music-video director Garth Jennings, and amounts to a cinematic karaoke session featuring 65 songs from names including Katy Perry, Taylor Swift, Lady Gaga and Stevie Wonder.

Set in a world inhabited entirely by animals, the owner of a theatre, koala Buster (Matthew McConaughey) is trying to keep his business afloat by holding a last-ditch talent show, with a voice cast that includes Reese Witherspoon, Scarlett Johansson and Jennifer Saunders.

And it's true: it needs little stretch of the imagination to see that Kelly, 23, and Meena actually have much in common.

Kelly, who grew up in a musical household in California, has been in talent contests since she was a child, once suffering with the same shyness and stage fright as seen with her on-screen counterpart.

"I think experience was a big thing," she says of overcoming nerves. "Every time I got on stage I felt a little more comfortable. I just learnt to shake off the butterflies. Any insecurities I had, once the music starts you've just got to get out there and do it."

Kelly went on to compete in American Idol in 2010. Unfortunately, fortune didn't favour her at the time and she failed to reach the final 24, but she took the bitter disappointment and turned it on its head.

She began putting acoustic covers up on YouTube and in 2012 scored a viral hit with her cover of Frank Ocean's Thinkin Bout You, which scored more than 26 million views.

"It had kind of a snowball effect," she says. "But it all started with just me having fun and not wanting to rely on people anymore and just getting back to the music."

The YouTube clicks translated into touring and her first album released last year, Unbreakable Smile, and she scored a number of award nods, including a Grammy nomination this year for best new artist.

Kelly says she knows it sounds cliche but her advice to young artists is never give up, and she hopes the movie reaches an audience in ways beyond its fun, colourful, animated menagerie.

"When you're watching the film, obviously when you walk in, you're like 'Oh, it's a bunch of animals', whereas by the end of the movie you forget that they're even animals," she says.

"You really feel that connected to them and you're invested in these people and following their journey.

"I think people are going to watch the film and find certain things about each character that they really connect to and they're going to see [the characters] overcome those fears that they've had and hopefully be inspired by that."

Sing is released in Australia on December 26.