We've all had that moment. You're flipping through the radio and - "YES!" your favorite jam just started - only to find out that it's actually a different song entirely. Thanks to the popularity of sampling in today's music, some of the biggest chart toppers contain snippets from older songs. And you may be surprised to find out exactly who's sampling who. From Rihanna taking cues from an '80s classic to The Fugees' re-work of Enya (?!), here are 6 major hitmakers that have made some unexpected choices in their sampling.