Complex sentence: Artists like Jay-Z and Lil Wayne have made it difficult to determine when an MC is freestyling a verse or recitting a written one; they who freestyle on their albums and features, so an on the spot freestyle is just a memorized verse.
Split into simpler sentences: Artists like Jay-Z and Lil' Wayne have made it difficult to determine when an MC is freestyling a verse or recitting a written one. These are two artists who freestyle on their albums and features, so an on the spot freestyle is just a memorized verse.