For this Halloween cover show this year, Phish got into costume on a whole new level, performing a cult classic album by a band that doesn’t actually exist: the Nordic prog band Kasvot Växt. The group and their album, í rokk, turned out to be Trey and the gang’s invention, after a bit of investigation. A fake backstory, however, was supported by an AllMusic review of the album, a backdated WFMU blog post, and even an interview. Now you can hear the band’s impressive stunt in full, which took place at the MGM Grand Garden Arena in Vegas. The alleged Kasvot Växt track list is complete with Phish-y titles that seem to show the band’s hand: “Turtles In The Clouds,” “We Are Come to Outlive Our Brains,” and more. Enjoy below.