Jonas Brothers Launch Tour With Guests Miley Cyrus, Jordin Sparks

The Jonas Brothers kicked off their massive world tour this past weekend in front of an audience 50,000 strong at Dallas' new Cowboys Stadium. The band's set featured a brand-new three-octagon stage and more than 100 minutes of music culled from their new album Lines, Vines and Trying Times as well as older material, but it wasn't until the encore that fans got the biggest surprise of the evening: Miley Cyrus, who's reportedly once again dating Nick Jonas, hit the stage and sang with Nick for their Lines' duet "Before The Storm," the Dallas Morning News reports.

(Relive the Jonas Brothers' opening date in our photo gallery.)

Rumors of Miley attending the show began circulating when Cyrus Twittered "In one of my favorite cities with my favorite people. Guess where I am and what I'm doing. I will never tell" earlier that evening. The Jonas Brothers were also joined onstage by opening act Jordin Sparks, who performed her new hit single "Battlefield" with the band. The set list also included A Little Bit Longer's "Lovebug, "SOS" and a cover of Neil Diamond's "Sweet Caroline."

"Putting this show together is so much different than anything we've ever done before," Nick recently told Rolling Stone when we hung out with the Brothers in the days before the performance. "We tried to add some musicians, some horn players and some string players, just to fill in the space, and fill in the sound as well." The trio also boast that the entire audience is only 30 to 90 feet away from the performers at all times, making the concert more intimate for the fans.

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