Joe Jonas poses with country countess Carrie Underwood as they attend the 2011 iHeartRadio Music Festival held at the MGM Grand Garden Arena on Friday night (September 23) in Las Vegas.

The 22-year-old musician was there as the biggest music festival kicked off — Black Eyed Peas, Carrie and others hit the stage and performed their biggest hits.

Joe recently chatted with Bop mag about one of the songs on his new album that means the most. “Most of the songs mean a lot to me, but ‘I’m Sorry’, is a song that I wrote as an apology to someone who’s heart I broke.”

10+ pics inside of Joe Jonas…