When Jack White isn’t busy looking grumpy at baseball games, he also sometimes plays music. A few nights ago at his show in Milwaukee (where he also sang Lorde’s “Royals”), he brought a fan onstage during his encore performance of “Seven Nation Army” and she got to jam with the band for a bit while wearing one of Jack’s hats and two of his guitars. Watch the video below — she comes on stage around 5 minutes in.