Los Angeles, Aug. 11 -- Jonas Brothers surprised their fans by bringing Demi Lovato as a special guest to their recent show, also reuniting her with ex-boyfriend Joe Jonas.

The concert was the first of the band's 20th anniversary tour, 'JONAS20: Greetings from Your Hometown,' reported People.

Several visuals of the concert, which took place at the MetLife Stadium in New Jersey, have surfaced online. Fans were taken aback the moment Demi stepped onto the stage and even performed 'Gotta Find You' from her and Joe's 2008 Disney film, 'Camp Rock.'

"Joe got the job, and then somehow our dad figured it out to get me and Kevin to be involved in the movie too. I think it's time that we all walk down this memory lane to celebrate a little movie...