Pearl Jam played a headlining set at Belgian multi-day festival Rock Werchter on Saturday night and brought with them a cast of guest performers including none other than singer-songwriter Jack Johnson.

Eddie Vedder invited Johnson onstage to cover John Lennon’s classic “Imagine” after taking some political jabs, suggesting that the audience light up their phones and sing along to show what a “really big crowd in harmony looks like.”

Other guest performers included MC5’s Wayne Kramer, Soundgarden’s Kim Thayil, and Fugazi’s Brendan Canty who joined Pearl Jam early in the set for a version of MC5’s signature “Kick Out The Jams.”