BBC Live Lounge covers—exposed, low-reverb, lining up artists of all genres to take a swing at straight-up pop—are a tune category all their own, as well as a significant test for a vocalist's charisma and flexibility. Favorites in recent memory include Kwabs on "Dark Horse" and Taylor Swift on "Riptide" (nice to see her songwriter's sincerity with her now-improved vocal control); favorites of a few years past include Florence Welch on "Take Care" and (this one is incredible) the Noisettes on "When You Were Young." Now, the synth acolytes of Chvrches turn their sparkling, ardent propulsion to Justin Timberlake's 10/10 hall-of-fame diss; Lauren Mayberry is too reticent and ambiguous a singer to fully inhabit the track, but it's a good listen nonetheless, and a strong opportunity to revisit Justin's very-sexy-to-my-teenage-self video.