Mathematics has taken over the rap game. Consider the evidence: (If you don't get any of these jokes it's because you do not belong to the highly specialized niche consisting of math nerds who listen to rap music. We are a very special and extremely finite group.)
T.I. is without a doubt a reference to the ever famous Triangle Inequality. The Triangle Inequality is not "Dead and Gone," it's just "Living It's Life."
Will.i.am of the Black Eyed Peas is dyslexic, and what he meant by "The i p's" (think about that one) was "The Pi's" a clear reference to the most significant irrational number unknown to mankind. Sure we know over 1,000,000 digits of Pi, but the fact that we don't know all the digits was an issue Will.i.am was bringing to national attention. If only he weren't dyslexic more people would have understood. "I Gotta Feeling" his song, "Meet Me Halfway" is a subtle reference to the fact that there is no halfway point with the decimal expansion of pi. "Boom Boom Pow" is Fergie's best way of describing how good it feels to sedulously solve a toilsome matrix analysis problem.
Biggie Smalls: It's pretty obvious he wasn't referring to the tiniest size available for a Wendy's shake. He was raising attention to number inequalities for his brothers in the 'hood. Elementary schoolchildren the world over have him to thank for understanding the notation 2>1.
Two-Pac: C'mon, any rapper that includes the only even prime number in his alias is assuredly a math aficionado.
Jay-Z: The letter 'j' is one of the most known indices of all mathematics, and of course Z is a generic complex number.
Yep, the evidence is abundantly clear. A celebrity is a rap star if and only if they are a math nerd.