WARNING TO CHRIS BROWN: Do not cheat on Rihanna. On her new Stargate-produced single, she goes bonkers when her boyfriend is unfaithful to her: "Grab your clothes and get gone/You better hurry up before the sprinklers come on." (In the video, the poor guy reaches his clothes only after she has already set them on fire.) Written by Ne-Yo, the ballad has the same sultry, clap-along rhythm of "Hate That I Love You," just with extra rage: "Trying to apologize?" Rihanna taunts. "You're so ugly when you cry." Ouch.

“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.