Shawn Mendes, Camila Cabello
Amy Poehler, Jack Black, The Rose
Harry Styles, Meghan Trainor
Justin Bieber, Cody Simpson, Home to Mama
Neil Patrick Harris, Jason Segel
Lady Gaga, Christina Aguilera, The Voice
Opening Act Performance: Jason Mraz and Jono
Kelly Clarkson Compares "Duets" To "Idol"
Ron Burgundy, Anchorman, Robin Thicke
John Mayer, Katy Perry, Who You Love