You never know who's hanging out at your jam session.

In a new video, a kid in Maui, Hawaii is playing his own rendition of "One Day," a song by rapper Matisyahu — completely unaware that the original artist is standing right in front of him.

We're not just talking "in the audience." No, Matisyahu is literally right there, wearing a strange and beautiful pair of sandals. And he's singing along.

"Watch the reveal at the end," wrote Stu Brooks, the director, producer and bassist for Matisyahu who posted the video. "He still didn't believe it was him and it took a second for it all to sink in."

To be fair, this is understandable. Matisyahu has changed his look a lot over the years. Plus, it makes the reveal all the more delightful — and probably saved the poor kid from some hardcore nerves during his performance.