Kelly Clarkson's "Shake It Off" Cover Proves She Really Is an 'American Idol'

It's official: No one can cover a song like Kelly Clarkson can cover a song.

Fresh off stunning the Internet with her "bluesy" rendition of Sam Smith's "Stay With Me," Clarkson is back with another cover you won't be able to stop listening to.

"This is a church song. This is a soulful song. This is one of my favorite songs out right now," she said at an appearance in Buffalo this weekend. "And you think you know it, but you don't. It's not Sam Smith."

With a setup like that, not even the audience knew what she was going to take on. Clarkson singing a gospel version of Taylor Swift's poppy "Shake It Off" was probably the last thing they expected.

Listen below to the stripped-down version before she pops into the song's peppy chorus at the 1:00 mark:

She's right, it's full of soul and an energetic take that, once again, proves why the original American Idol is a chart-topping success with the longevity to match. Hell, even Swift herself recognizes what a pop queen Clarkson is:

Duet, anyone?