2099 (feat. Troye Sivan) - Montell2099 Remix

Charli XCX's first collaboration with Troye Sivan was her nostalgic anthem "1999." A year later, the pair reunited for a futuristic new song; "2099" travels exactly 100 years from their previous hook-up.

Lyrically, the song is a sweary, braggadocios track sung primarily by Charli XCX. She spends much of her sole verse touting her superiority over a competitor. The songstress is joined on the chorus by Sivan. I'm Pluto, Neptune, pull up, roll up, future, future, ah The pair will continue to be top of the game well into the future.

Charli explained to Apple that after they'd recorded "1999," she suspected Sivan "wanted to get a little bit weirder than we got," as she'd heard him mention he was into her experimental mixtape Pop 2. She added: "After '1999' came out, I hit him up again and said, 'Should we just go there? Should we just go out of space? Like, let's do a weird moment.' And he was like, 'Yes, let's do it.'"