Watch Jason Aldean Address Las Vegas Shooting and Cover Tom Petty on 'SNL'

Jason Aldean, the country singer who was onstage when a man opened fire and killed 59 people at a music festival in Las Vegas last Sunday, was an unannounced musical guest on last night's Saturday Night Live. He took the cold open to address the pain caused by the shooting and to issue a message of solidarity, before performing a cover of the late Tom Petty's "I Won't Back Down."

"This week we witnessed one of the worst tragedies in American history," Aldean said, staring directly into the camera. "Like everyone, I'm struggling to understand what happened that night, and how to pick up the pieces and start to heal. So many people are hurting: there are children, parents, brothers, sisters, friends. They're all part of our family. So I want to say to them: we hurt for you and we hurt with you. But you can be sure that we're gonna walk through these tough times together every step of the way. Because when America is at its best, our bond and our spirit—it's unbreakable."

Aldean and his band then dropped straight into "I Won't Back Down," both as a reinforcement to his speech, and as a tribute to Petty, who died Monday at the age of 66.

Watch the full cold open at the top of the page.

Follow Noisey on Twitter.