The highlight of this collaborative set is "Days/This Time Tomorrow," a medley of Kinks classics. Done pub-chorale-style with banjo and upright piano, it pairs Ray Davies with Mumford & Sons, tipsy folk rockers who share with Davies a profound Englishness. For every dud (the world needs no more "You Really Got Me" covers), there are three gems (Spoon's title cut, Jackson Browne's "Waterloo Sunset," Black Francis' "This Is Where I Belong"). Most, go figure, are with Americans, and none are more poignant than the late Alex Chilton singing "'Til the End of the Day." But Davies' songbook is so deep, this could be a box set.

Listen to "Days/This Time Tomorrow":

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“I'm Yours”

Jason Mraz re-emerged after his disappointing second album with this lead single, a Jack Johnson-esque ditty about giving yourself fully to someone else. The success of the reggae-tinged song (it earned two Grammy nods and a spot on the Billboard singles chart for well over a year) was something the folk-pop singer never predicted when he wrote it in 15 minutes at home. "I played a happy-hippie chord progression that would probably work without 50 different Bob Marley songs," he told Rolling Stone. "I thought, 'It's too novelty. This is a nursery rhyme,'" concluding that "you can never guess what's gonna be a hit."