DJ Windows 98, better known as Arcade Fire’s Win Butler, performed a DJ set at the Phi Centre in Montreal last night (September 10) and a few famous friends stopped by to join the party. Special guests Diplo and Madonna, as well as fellow Arcade Fire member Régine Chassagne came out onstage to help get the party started and danced around.

Despite a studio spotting of Diplo and Skrillex earlier this summer with Butler and Chassagne—where the guys played it as “just showing a couple of friends [their] studio”—Diplo has since confirmed that the four are in fact working on beats together. Well, if that’s the case, it’s no surprise his fellow and future bandmates were in attendance. And Madonna, well she’s just Madonna and can pretty much take any party to the next level.

Check out the photos and video below.