Cooper — who also stars in the film — just broke the fourth wall in a major way with its latest frame. He took the movie across the pond and filmed a scene at Glastonbury, going as far as joining American rock icon Kris Kristofferson onstage during his music festival set.
This is a big deal in and of itself: Glastonbury is one of the biggest music fests in the world, and though Bridget Jones had a run-in with Ed Sheeran in Bridget Jones's Baby in one of the Glasto tents, no movie's gone so far as to crash a nonfictional fest to this degree.
That's not the only surprise, though: It turns out that Gaga isn't the only musician attached to the project, and that there may have been more to her Metallica collaboration at the Grammys after all.
Let's take a closer look at the cameraman. Onstage with Cooper and partly obscured by the lens of his camera, you'll see Lars Ulrich — Metallica's drummer — at work, which means one of two things: He's either playing a cameraman or crew member in the movie, or he's actually flexing his film chops and working on the crew of A Star Is Born.
Gaga dropped a pretty subtle clue that this was a possibility in February in an interview with Entertainment Weekly when she revealed that the idea for the Metallica/Gaga Grammy performance sprung up after Cooper introduced her to Ulrich.
Maybe they were running lines for the movie, or at the very least talking about it when the prospect of MetalliGa came up. Either way: Whoaaa. Guess we'll have to wait until September 2018 to see whether Ulrich is helping out Cooper on the production front or if he's hopping in front of the camera himself.