Jay-Z is shattering walls and glass ceilings that have long held back hip hop. In 2011, he broke Elvis' record for most No. 1 albums by a solo artist. In 2004, he became CEO of Def Jam, one of music's biggest labels. In 1999, his Hard Knock Life tour showed that rap could fill arenas. Rap is now widely accepted as part of mainstream pop culture, and Jay is a big reason why.