9. “Who You Love”
“My boy ain't the one that I saw coming/And some have said his heart's too hot to hold” —Katy Perry
Returning to her roots as a gospel and Christian singer is Katy Perry, who delivers on a duet with Mayer much like Feist did on Wilco’s “You and I.” In a track about finding love where you've never looked and forever remembering the best thing that you had, Perry’s voice perfectly compliments Mayer’s sorrow. The downside is hard: Perry can never have the boy she dreams of, with her own inhibitions and distance between them. His “hot” heart wanders off with hers.