The "Breakaway" singer, whose daytime talk show returns next week, sat down with Jimmy Fallon for a music-themed game on Friday's episode of The Tonight Show in which they attempted to identify several songs played backwards. However, the boy band's 1999 hit "I Want It That Way" left Clarkson — and Fallon! — totally stumped.
When Questlove later revealed its title, Clarkson looked confused as she replied, "What's that?" But she did seem to recognize the song after it was played normally, scrunching up her face and knocking a fist on Fallon's desk.
"I wasn't a boy band kid!" she announced.
Outraged by her confession, Fallon let out a gasp and replied, "That's a classic!"
"They're great. I just wasn't a boy band — I didn't know that one," Clarkson admitted. "I wouldn't know it forward."
The good news? Clarkson is game to rectify her fatal error in the future. "I know! I'll do it now," she said. "Thank you for all the ideas."
Todd Owyoung/NBC via Getty; Rob Kim/Getty Kelly Clarkson; Backstreet Boys
Things only got more difficult for Clarkson throughout the rest of the game, as she failed to recognize Edwin McCain's "I'll Be" and Miley Cyrus' "Wrecking Ball."
"I feel really confident about myself right now," she joked.
The worst moment, however, came when she missed her own song "Stronger" in the final round, causing a stunned Clarkson to leap out of her chair, wave goodbye to the audience, and pretend to almost walk off stage.
"Oh my god," she said. "Wow."
Watch Clarkson and Fallon go toe-to-toe in the clip above.
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