season 21 finale!The 56-year-old Nashville-based singer has been a frontrunner all season, but her finale performance of «Over the Rainbow» brought the house down at the end of Monday's live finale performance, leaving the coaches on their feet and speechless.«I don't think i've ever seen anyone with a gift like you have,» John Legend raved. «And then you just stand there and do it with nonchalance!..