Two of today's biggest female pop acts took to the stage at Lollapalooza in Chicago this past weekend to dip into some vintage '90s girl-power.

The 1990s were a glorious time for music and massive concerts with billings that could barely be believed. Not only did Lollapalooza get its start in that era (before going away and coming back in the new millennium), but the Spice Girls also defined an era of female power pop that inspired a number of today's acts when they were wee children.

Those two worlds collided at Lollapalooza 2017 in Chicago this past weekend, when British sensation Charli XCX teamed up with Halsey to give fans in attendance a once-in-a-lifetime performance of the Spice Girls' star-making single "Wannabe." Both twentysomething artists did their best to cover the parts of all five Spice Girls despite the fact that they were the only two singing. It's hard to tell just how into the crowd was given the audio mix being so focused on Charli and Halsey, but if we were bopping and singing along at home, we have a feeling there were plenty of people in the crowd doing the same.

We'll even forgive Halsey for not knowing all the lyrics exactly, as she's a few years younger than Charli XCX, and she didn't grow up in Britain where Spice World was all the rage. At least this jam remind us that sometimes you do gotta zig-ah-zig-ahhh.

Pop Albums Turning 20 This Year

More From PopCrush