Sydney Bourbeau was half way through covering Ed Sheeran's "Thinking Out Loud" at West Edmonton Mall on Sunday when Sheeran himself, who just happened to be at a nearby music store, hopped on stage and helped her.
The 13-year-old Grade 8 student says she initially thought Sheeran, who was wearing thick-rimmed glasses and a plaid shirt, was a stage hand coming to help her with the microphone stand.
With the crowd roaring its approval and people scrambling for their phones, Sheeran and Sydney shared the mic for a verse and a chorus.
Then, giving Bourbeau a hug, the British megastar was gone as quickly as he arrived, allowing the youngster to finish up.
Sydney was performing at the mall as part of a concert to mark the end of a fundraiser for the Humane Society hosted by her music school Resonate.
She says Sheeran's manager got in touch with her later that day to offer her tickets to Sheeran's show in Edmonton that night.
He sent her a message again during the show asking her if she wanted to come backstage, but she didn't see that one until after she was already home.
Still, she says the encounter, which has been posted by a handful of different people on social media, made her pretty popular at school on Monday.
"It was nuts," she says.
"Like everyone at school knew and they were all like, 'Oh my goodness, you are famous! Wow, this is creepy.'"