The untitled project was completed in a single day, and features nine songs. There's a good chance you'll never hear it though: "It will probably never come out but it might be AMAZING who knows?" Charli wrote on Twitter.
Cook collaborated with XCX on her EP Vroom Vroom and Number 1 Angel mixtape, for which Cook recently shared his track-by-track notes.
Charli XCX discussed the possibility of new music last week in an interview with The FADER: "I just write so much that it becomes confusing. Of course, some of the stuff I write isn’t good — some of it is terrible and will never see the light of day — and some of it is good, you know. I might do another mixtape before the album though." Her new album is projected for a 2018 release.
PC Music is currently releasing new music every day in May as part of the label's "Month of Mayhem" campaign.
Representatives for Charli XCX were not immediately available for comment.