UPDATE: A much closer video of the performance has popped up on YouTube.

ORIGINAL STORY

Charlie XCX had a little surprise in store for the crowd at the annual Lollapalooza Festival in Chicago over the weekend when she pulled her soon-to-be tour mate, Halsey, on stage for a cover of one of the greatest girl power anthems ever written, "Wannabe" by the Spice Girls.

Fortunately for those of us not in attendance, Twitter user, @scottgum, founder and Editor-in-Chief of music blog, Stereogum, was in the crowd and captured a good portion of the performance on video. Admittedly, he wasn't as close to the stage as he would have liked, but the sound quality is still pretty good. Take a look:

According to Billboard, Halsey wasn't on the lineup for this year's festival, so it's unclear why she was there in the first place. Maybe she's simply like the rest of us and just loves listening to her favorite artists play live.

This cover may become a nightly occurrence as Charlie is set to hit the road as Halsey's opening act on her Hopeless Fountain Kingdom Tour beginning in late September. The closest the tour will get to the Evansville area is Rosemont, Illinois (just outside Chicago) on November 19th.

[Source: Billboard.com]