The Roots' 13th release is a concept album with a bravura twist: It narrates the story of a bootstrapping hustler in reverse, from death to birth. The morally ambiguous gangster tale is a pop-culture staple; unfortunately, Black Thought’s skilled but stolid rapping adds nothing new to the idiom. Sonically, though, undun is a knockout, sliding between genres, with the slinky digital grooves of songs like "Sleep" rubbing against the guitar-anddrums assault of "Stomp." The record ends with a three-part instrumental, including some mighty Elvin Jones-style bashing by Questlove – a musical coda more gripping than the saga that preceded it.

“1999”

“I don’t consider myself a great poet,” Prince told Rolling Stone. “I just know I’m here to say what’s on my mind.” In the case of the apocalyptic party anthem “1999,” he was worried about then-president Ronald Reagan’s foreign policies. The song’s melody is based on a riff borrowed from the Mamas and Papas’ “Monday, Monday,” and Prince originally envisioned the first verse with three-part harmony but later split the vocals between himself and members of the Revolution. Because Warner Bros., with whom Prince was locked in a contractual battle, owned the original’s masters, Prince rerecorded the song and appropriately released that version in 1999.