Near the very end of Bon Jovi‘s final show of their nine-night residency at Madison Square Garden on July 26, Jon Bon Jovi told the crowd he was going to welcome a special guest to the stage. “For 50 years he has been a beacon of light and truth,” he said. “Will you please welcome my friend, my brother, and the poet laureate or our series of rock & roll. Ladies and gentlemen, the one and only Bruce Springsteen. The king of the great state of New Jersey.”

As the crowd erupted, the band kicked into “Who Says You Can’t Go Home” from Bon Jovi’s 2005 LP Have a Nice Day, with Bruce and Jon trading vocals. They followed it up with Springsteen’s 1978 classic “The Promised Land,” before the two titans of New Jersey locked arms, raised their guitars, and came together for a group bow.

Last month, Jon Bon Jovi appeared at Springsteen’s Music America: The Songs That Shaped Us concert series at Monmouth University. Bon Jovi played “Johnny G. Goode,” and then later appeared alongside Springsteen for “Raise Your Hand” and “I Don’t Want to Go Home.”

The surprise Bon Jovi appearance at Madison Square Garden was the culmination of a very busy weekend for Springsteen. On July 24, he received the ACLU’s inaugural Ralph Ellison Award for Defenders of Civil Rights and Civil Liberties in the Arts, Business, Science and Sports at the Washington Hilton in Washington, D.C. He played “Streets of Minneapolis” at the ceremony. The following night, he brought his sister Pamela to John Mellencamp’s Greatest Hits tour at the PNC Bank Arts Center in Holmdel, New Jersey, but didn’t get onstage.

Prior to these nine Madison Square Garden shows, Bon Jovi had been off the road for four years while the singer recovered from a severely damaged vocal cord that required surgical intervention. “I’m fully recovered,” he told People in June. “It was longer than I’d ever expected, but it had to be right. We never lost faith.”

Bon Jovi did, however, end the July 23 MSG concert slightly early due to a sinus infection. “I’m sorry, I’m hurt and you’re not getting the best of me,” he told the crowd. “Don’t throw away your ticket stubs, I’m gonna figure something out, OK? Just hold onto it, we’ll figure out how to reschedule. But I’m gonna have to cool it for the night.”

The Bon Jovi tour resumes Aug. 28 at Scottish Gas Murrayfield Stadium in Edinburgh, Scotland. It then moves to Croke Park in Dublin, Ireland, and wraps up with three nights at London’s Wembley Stadium.  Nothing is confirmed at the moment, but it’s very likely that additional dates will be added.

Springsteen, meanwhile, has nothing on his calendar until Oct. 3, when he’s slated to make an appearance at Tom Morello’s Power to the People festival at the Merriweather Post Pavilion in Columbia, Maryland. It’s a packed bill that also includes Foo Fighters, Dave Matthews, Joan Baez, Brittany Howard, Dropkick Murphys, Jack Black, Serj Tankian, Cypress Hill, Killer Mike, Taylor Momsen, Matt Cameron, the Linda Lindas, and Darryl “DMC” McDaniels.