In an interview with GQ Magazine, Junkie XL, aka Tom Holkenborg who will score the upcoming Zack Snyder-directed Justice League, revealed some details regarding how the Justice League trailer came together and who was the person to come up with the song for it.
“For the title song at the end of 300: Rise of an Empire, I took the vocals for Ozzy Osbourne’s “War Pigs” and created a whole new track around it, so it became a reworked version of the original,” Holkenborg revealed. “That was Zack Snyder too. And [for Justice League], he said, “Ohhhh. You know that thing you did back in the day with Ozzy Osbourne? Can we do something like that for the trailer?” And that’s how it all started.
“[“Come Together” is] me and Gary Clark Jr. That was an amazing collaboration. There was an idea to do something with that track for the trailer. They asked me, we started brainstorming, and we approached Gary. He was really up for it, and we spent a couple of days in the studio. [It didn’t take] that long. It was pretty clear to me what I wanted to do.”
As of now the specific track from the Justice League trailer has not been made available but Holkenborg on his own personal Twitter account told people to stay tuned!
— Tom Holkenborg (@Junkie_XL) April 24, 2017
Junkie has worked on previous DC films, having already been a creative force for the score of Man of Steel and Batman v Superman: Dawn of Justice with the help of his fellow European composer, Hans Zimmer. So he is definitely the man to create the score for Justice League.
Source: GQ
(Updated with clarified information April 25)