AceShowbiz -

Kelly Clarkson has proved herself as a professional singer in the latest episode of "The Tonight Show Starring Jimmy Fallon". After talking about fellow "The Voice" coach Blake Shelton, Jimmy Fallon challenged the 35-year-old singer to sing a song backwards. Kelly looked flustered at first, but she eventually accepted it.

Jimmy also mentioned about a guy on YouTube who could sing backwards without failing, asking whether or not Kelly has done it before. Well, she hasn't. "Can't say that I have Jimmy," she said while laughing. "I don't just sit in my room and go, 'Wonder what this would sound like backwards?' "

Kelly looked confused when she started singing "Since U Been Gone" backwards, but she quickly adjusted to the lyrics, completely nailing the song. She received a lot of cheers from the audience when she sang the chorus, showcasing her incredible vocal. Jimmy, on the other hand, couldn't contain his excitement. He got up from his seat and danced behind the "Because of You" hitmaker, showing off some crazy moves.

Also on the show, Kelly and Jimmy went back to the past when they reminisced about their first meeting. "The Voice" coach joked that Jimmy was lucky to have met her, gaining a laughter from the audience. The show's host also brought a picture, which led them to make fun of themselves, from their first meeting. Jimmy remarked that he looked like an old-time gangster in the picture, while Kelly said she seemed like she wanted to be a skunk.

After that, the first winner of "American Idol" talked a bit about her new children's book "River Rose and the Magical Christmas", which was named after her daughter. "She think it's her book," Kelly said. "As in we went somewhere, and somebody had one, and she was like, 'Why do you have my book?' She's kind of mean about it."

Concluding her appearance on the show, Kelly performed one of the tracks off "Meaning of Life", "Whole Lotta Woman".