Apparently The Police drummer Stuart Copeland just invites people over to his house to jam now, because why not? The above video features Copeland on guitar, Rush's Neil Peart, Tool's Danny Carey and South Park creator Matt Stone on drums, Vertical Horizon frontman Matt Scannell on bass. Additional musicians later provided the other layers you hear, but holy hell you guys- Carey and Peart are aware of each other as musicians and got together on a song to drum simultaneously.
Good luck picking up your brain from the floor.