The filmmakers behind the much-anticipated animated movie cleared the rights for the 1986 track and Simon & Garfunkel's classic track The Sound of Silence before Justin came on board as a first-time executive music producer, and he was tasked with revamping the 30-year-old tune for the doundtrack.

"I was very nervous, to be honest," the SexyBack singer tells Collider. "I remember the whole time I was doing the recording session, I was like, 'What is Cyndi gonna think?' I still don't know, and I guess it's too late to worry about it, because it's already in the movie."

Timberlake admits creating new songs, like Can't Stop the Feeling, and reworking classics was a real challenge, but he hopes he came through with flying colours.

"This is my first time doing it, on this level," he adds. "For a musical like this, to take these classic toys (Trolls) and mythological creatures from so long ago and really modernise them, that was our M.O. with the music, as well... Some seven-year-old is gonna walk away knowing The Sound of Silence, which is very cool, and a song like True Colors.

"I came on a little after some of the songs were sought after and cleared. I don't know if you know about the clearance process, but that can be mind-numbing. So, when I came in, True Colors was definitely already picked out for this moment in the movie. The Sound of Silence was already picked out, too. So, my job for that was just hopefully to put our own spin on it, make it sound unique, and make it sound like it belonged in the scene, much like musical theatre, almost."

Justin also wrote four original songs for the movie, in which he also stars.

"Overall, you'll feel that a lot of the music definitely has a little bit of '70s funk to it, so that was definitely an inspiration," he adds.