Demi Lovato Challenged James Corden To A "Diva Riff-Off"

Demi Lovato was a guest on The Late Late Show with James Corden last night, where she challenged him to a good old “A Cappella Diva Riff-Off.”

The two sang hits from diva superstars Adele, Cher, Aretha, Tina Turner and Katy Perry! Check out the video and let us know who you think aca-crushed it! 😉