Billie Eilish and Finneas performed acoustic renditions of "Wildflower," "The Greatest," and "Birds of a Feather" at FireAid.
Kelly Clarkson took on Billie Eilish's Grammy-nominated song "Birds of a Feather" for her latest Kellyoke performance.
Who will win big at the Grammy Awards this weekend? Breaking down Best New Artist, Album of the Year and more.