Rihanna's at the point where she can take three years between albums if she wants; broken release dates aren't going to knock her off her throne. That's hardly the case for every artist, though. In fact, Rihanna's security just emphasizes how precarious the pursuit of super-duper-stardom has been for many of her peers. When Rihanna reached Music of the Sun in 2005, there wasn't any way to know that 10 years later she'd be an invulnerable icon. And to see just how invulnerable she is, you only have to look at other folks who stumbled over the barriers that she can now safely ignore. Here are nine of them.