So much about having longevity in hip-hop depends on rappers being able to exist within the times and re-invent themselves if needed. Some rappers have taken that re-invention more literally than others. Here are 63 rappers who chose, for one reason or another, to taken on new rap names as their careers have gone on. Sometimes they've gone back to their original monikers and other times they've just stuck with their first choice. What's in a name? Check out the changes over the years in the gallery above.