At a recent concert, Michael Buble stopped the show to talk to a seemingly crazy lady who was heckling him from the front of the stage.

 

In talking to her, he discovered that her son, Sam, had recently had his 15th birthday, and apparently was a good singer.

Buble had his doubts, but said, "I remember what it was like to be that age, come on up here."

So, up to the stage walks Sam (I kind of judge him based on his shirt choice, but whatever. What came next surprised even Buble! Check it out after the jump!