Charli XCX, Halsey Slay Spice Girl's 'Wannabe' At Lollapalooza

There are so many reasons to love Charli XCX!

Fresh off the release of her fab new single and video, "Boys," the British singer/songwriter hit the stage at Lollapalooza over the weekend.

And during her set, she and Halsey slayed the festival audience with a throwback cover of the Spice Girls iconic pop hit, "Wannabe."