This 7:36 track is a concoction of R&B, funk and electro and choral segments. There are flashes of tweeting birds, eerie piano and a disorienting extended selection of spliced and warped sounds recorded on Weller's iPhone. "It's supposed to be like sound pictures," Weller told Q magazine of the aural collages. "It's a little journey. It's the first song on the album, so you're thrown in the deep end and I like that."
Lyrically, the song is about people going for a night out clubbing. "I imagined all these kids lining up outside a dancehall," Weller told Mojo magazine. "It could have been the Wigan Casino, or somewhere today - whenever, whenever. And once they are inside, it's when their lives come alive. They're united... and ignited by the music. It's a song about the power of music."
Weller cut "Mirror Ball" around the same time as his 2018 True Meanings album. The bold, shape-shifting song was not a fit for that record's stripped-back, acoustic sound, so the Modfather earmarked it as a bonus track. "We played it to a few people and everyone flipped over it," he recalled. "I realized it was too good to be a bonus track. It had a lot of the qualities that I was looking for - that kind of soul thing, but it had the slightly abstract, avant-garde thing going on as well."
Longtime collaborator Steve Craddock pops up to deliver his trademark guitar sound on the track. He also plays the Moog synthesizer.