Anne Hathaway kicks things off with "Love" by Mary J. Blige. Emily Blunt hits back by getting down to "No Diggity" by Blackstreet.
Emily Blunt channels Janis Joplin (eerie, isn't it?) as she takes on "Piece of My Heart" in the final round against Anne Hathaway and her spectacular interpretation of "Wrecking Ball" by Miley Cyrus.