Mike Campbell and the Dirty Knobs and Dwight Yoakam have been opening the West Coast swing of Chris Stapleton's All-American Road Show tour and at this past weekend's L.A.-area shows, Campbell joined Chris and company to cover "I Should Have Known It" from his old band Tom Petty and the Heartbreakers' 2010 album, Mojo. You can find good video of Friday's performance of it on YouTube.