"All I want for my birthday is a big booty call," Atlanta rapper 2 Chainz barks on his new single, underscoring his zest for rap's simple pleasures – a slinky strip-club beat, a burial plot in the jewelry store and a hyped-up Kanye West cameo. "Birthday Song" doesn’t have the casual brilliance of his 2011 hit "I Spent It," but 2 Chainz is clearly cut from the Lil Jon/Waka Flocka Flame mold, where good-natured charisma can trump talent.

Listen to "Birthday Song":

“The A Team”

This debut track from the then-20-year-old British singer-songwriter has a dark story behind it. Sheeran says he culls songwriting inspiration from "viewing other people's situations," which, for the heroine in "The A Team," involves drug addiction and prostitution that began as a teen. Sheeran paints the woman's trials with haunting imagery such as "But lately her face seems/Slowly sinking, wasting/Crumbling like pastries." "I did a gig at a homeless shelter, [and the song] is about one of the women there. It's her story," he said.