Rakim’s influence is all over contemporary hip hop (and beyond it), from Tupac and Jay-Z to Eminem and Rage Against the Machine. He releases his third solo album, “The Seventh Seal,” today ? his first solo album in nine years. Morehouse College professor David Wall Rice talks with us about why Rakim is so respected in hip-hop circles, and why he’s relatively unknown outside hip-hop despite his wide-ranging influence.