Justin Bieber ties with Toby Keith in 10th place, with $55 million [photo: George Pimentel/Wireimage]Though he's only 18 years old, Justin Bieber has had a year for the ages. The Canadian crooner released his third studio album, launched a world tour and continued investing in startups, adding to a portfolio that includes stakes in Spotify, Tinychat and others. All in all, he earned $55 million in 12 months.

"I do calls every week with my business manager and my lawyer," Bieber told FORBES this spring as part of a cover story on his budding venture capital career. "Each week I'm learning something about my business and what I need to know for my career."

But when it comes to the world's highest-paid musicians, Bieber is a relative pauper, barely breaking the top ten.