Fans at MetLife Stadium were thrilled when Bruce Springsteen made a surprise appearance during Zach Bryan’s concert on Sunday night. The duo performed Springsteen’s classic “Atlantic City,” creating an unforgettable moment for the New Jersey crowd.

The exchange of sharp insults between Bruce Springsteen and Donald Trump has escalated, turning increasingly personal and nasty. From “Dried out prune” to “Corrupt” and “Incompetent,” the feud between the rock icon and the former president is heating up.