The song originated as one of several ethereal instrumentals Matt Bellamy had filed away. "I've always had these pieces of music, usually piano-based, that are these meandering-dreamy things that I write but don't always fit with Muse," he told NME
. "I just put them to one side and think, 'That could work for a film soundtrack one day.' 'Tomorrow's World' was one of them, and then during lockdown I just started singing on it."