For this year’s Grammys, Katy Perry is performing, fresh from the Super Bowl. Sia is performing, fresh from Saturday Night Live. But as always with these annual Grammy shows from executive producer Ken Ehrlich, the most anticipated music acts are the pairings. This year, they’re scheduled to include Hozier and Annie Lennox; Rihanna, Paul McCartney and Kanye West; Adam Levine and Gwen Stefani; and Tom Jones and Jessie J.