It's been almost three years since Avril Lavigne played a concert and nobody would have guessed she'd break her streak the way she did on Friday night (Sept. 8). Surprising the crowd at the Greek Theatre in Los Angeles, Lavigne came out and joined Nickelback on their song "Rockstar," sharing a stage with 'Back singer Chad Kroeger two years after the pair ended their two-year marriage. 

"You never know who will join us for 'Rockstar' karaoke," the band wrote about the surprise guest appearance. 

 

The band also invited up a fan named Own to jam with them on the song that serves as an audience sing-along during their shows.

Lavigne, 32, has been lying low for several years following her disclosure of a difficult battle with Lyme disease and in a post about her "Rockstar" cameo she wrote, "Good to be back on stage! Feeling excited, happy and grateful."

 

The good news for fans is that she's hard at work on her next album, as evidenced by this in-studio post from last week. Lavigne thanked fans earlier this month for their patience as she works on her upcoming album, telling them "It's been a long recovery and I want to make sure that this is perfcet for you guys!!" The still untitled effort will be the follow-up to Lavigne's 2014 self-titled album, which peaked at No. 5 on the Billboard 200.