Bruno Mars doesn't do low stakes. He is a drama king, a man who thrives on grand statements, soap-opera plotlines and actual-opera melodrama. On his second album, Mars sings endlessly about sex – wild, wind-swept, Wagner­ian sex. The smuttiest song here, "Gorilla," has a backbeat that would make Mutt Lange quake in his boots and a lyric that R. Kelly would kill to have written: "You're bangin' on my chest/Bang, bang/Gorilla . . . you and me, making love like gorillas."

From another performer, the bombast might be a deal-breaker, but from Mars – a master song-crafter and a nimble, soulful vocalist – it is the stuff of great pop. As on his 2010 debut, Doo-Wops & Hooligans, he infuses his songs with old-fashioned crooning as classily antique as his wide-brimmed fedora. But there's lots more: creamy Michael Jackson/Prince-schooled disco soul ("Treasure"), frazzled Police-style rock reggae ("Locked Out of Heaven"), Elton John-like balladry, Def Leppard grandiosity, dub reggae, all couched in beat-savvy modern production (Diplo, Jeff Bhasker, Mark Ronson). The result is a record that makes the competition sound sad and idea-starved by comparison.

Listen to 'Unorthodox Jukebox'

“Help Me”

Joni Mitchell wrote and recorded this song for her album Court and Spark, but she had to switch from her regular band to make the song sound exactly the way she wanted. "I had attempted to play my music with rock & roll players," she told Rolling Stone. "They’d laugh, 'Awww, isn't that cute? She's trying to teach us how to play.'" Mitchell switched to a jazz band, Tom Scott’s L.A. Express, and scored the biggest hit of her career in the process.