Green Day's Billie Joe Armstrong opens up in Rolling Stone's cover story.

+ Green Day frontman Billie Joe Armstrong opens up about his years battling substance abuse, the events leading to his recent stint in rehab, and his road to recovery in this week's Rolling Stone cover story, which hits stands on Friday. (Rolling Stone)

+ In more Green Day news, the group will resume the arena tour they postponed when Billie Joe Armstrong entered rehab. The arena tour launches March 28 in Rosemont, Ill., and ends April 18 in Los Angeles. They'll also perform three intimate shows prior to hitting the arenas. (MTV News)

+ Check out Justin Bieber's new "X"-shaped tattoo, which he shared on Instagram! (Just Jared Jr.)

+ Justin Timberlake and Mumford & Sons' Marcus Mumford have teamed up for a song. The track will appear in "Inside Llewyn Davis," a Coen Brothers' film that JT and Mumford's wife Carey Mulligan will star in. (MTV News)

+ Kanye West has been on a rant roll (kinda like a rick roll: awkwardly funny, but with more expletives) while touring Europe, and his stop in Paris was no exception. He dropped some good news, too. "I wanted to let you know, I'm working on my new s***," he said. (RapFix)

+ Demi Lovato chatted with Ryan Seacrest about her new "Heart Attack" single yesterday. "[It's about] other situations where I felt abandoned in my life and when you open up your heart to somebody, it's a risk. And this song is about taking that risk," she explained. (MTV News)

+ Time to get schooled: J. Cole visited Harvard University to drop some hip-hop knowledge at an event called "The Next Move: A Conversation with J. Cole." Watch footage from the discussion. (Rap-Up)

Photo credit: Rolling Stone/Danny Clinch