Summer festival season rolled along this weekend with Chicago's Lollapalooza, and among the many spectacular musical moments comes this highlight: a Spice Girls cover featuring none other than Charli XCX and Halsey.
Why did this amazing collaboration happen? Simple, Charli had a set at Lollapalooza and brought out the pop singer for a special guest appearance. Watch one of the best musical moments of Lollapalooza's 2017 below:
Both Halsey and Charli teased the appearance on their instagram the night before while posting a photo of them having a "slumber party".