Grateful Dead superfan Andy Cohen has been giving Jimmy Fallon homework ahead of his first Dead & Co. show this Halloween. It may seem like a rogue AI came up with that sentence based on “Things vaguely affiliated with John Mayer,” but it’s true. You’d think it would be the other way around, but Andy Cohen likes to jam out on occasion and Jimmy Fallon has yet to partake. Andy has been giving Jimmy three Dead songs a week to master, both studio cuts and bootlegs. And tonight on Watch What Happens Live, Fallon’s gratefulness was tested. He crushed, then did the running man, probably the first time that dance was associated with the Grateful Dead. John Mayer is going to be so proud on Halloween.