I want to hear mainstream rappers go off the top cus lets be . ANYBODY can write a verse if you give them some time..... except Soulja boy tho, that nigga just writes jingles...
and just to enlighten ppl.. "freestyle" can mean anything that was completed without a theme/concept in mind (freestyle dance/freestyle art) -- it is free of style, its random.. with regards to music, as soon as lyrics are composed around a theme/concept in mind, those lyrics become part of a "verse", not a freestyle, usually paired with another verse of similar theme to make a "song" .. now, a verse written without a topic is considered to be a written freestyle, those are called "freeverses"