Rapture, a "joy excessive and sweet," as Spain's great mystic Saint Teresa of Avila, described it in her 1563-65 diary, can be achieved variously by music, religion--and hallucinogenic drugs such as the Amazonian religion-enhancer ayahuasca. Neurobiologists have tracked at least some of the peak experience of music to at least one cause, the release of the transmitter molecule dopamine within the striatum of the brain. The same biochemical reward system also mediates pleasure in food and sex. Because music began in paleolithic times. . . and because it remains universal in hunter-gatherer societies around the world, it is reasonable to conclude that our loving devotion to it has been hardwired by evolution in the human brain.
In almost all living societies, from hunter-gatherer to civilized-urban, there exists an intimate relation between music and religion. Are there genes for religiosity that prescribe a neural and biochemical mediation similar to that of music? Yes, says evidence from the relatively young discipline of the neuroscience of religion.
--from E.O. Wilson's The Meaning of Human Existence.
I suppose that applies to rock and hip hop too. Eventually we may learn whether Franz Schubert and Justin Timberlake generate different chemical brews within the striatum of the brain. As for Jay Z, I can only wonder.