Rap is a funny thing. While many stereotypes about it exist, it does truly transcend common music balance. By Merriam Webster's own definition, rap is "...rhythmic chanting often in unison of usually rhymed couplets to a musical accompaniment...". In that sense...there are none greater than Leonard Cohen and Bob Dylan. Both are giants of rap. In terms of popular culture though, there is only(and will only ever be) one name associated with true rap. That name is NWA.