At a show in Connecticut last week, Michael Buble noticed a 21-year-old girl named Chelsea Hebert in the audience. She was holding a sign that said "Let me sing with you, Mr. Buble". So Michael invited her up...and she CRUSHED IT.

Apparently, she's had no professional training and has never auditioned for any talent TV show...which is leading to some speculation it was totally a plant. Either way, ya can't deny her talent...