In 2013, as has been true for the past few years, much of the best rap music came via free mixtapes posted to the various aggregating web sites (DatPiff, LiveMixtapes) that have sprouted up in response to what has become a booming cottage industry. Mixtapes are now where hit singles and real careers are birthed, and where established rappers return to prove they still have it. Here are our 10 favorites from this year. 

BY JORDAN SARGENT