Rapper Tupac Shakur, who died at age 25 in a 1996 shooting, recently made headlines when he appeared on stage with Snoop Dogg and Dr Dre at the Coachella 2012 festival. The Tupac “hologram” performed Hail Mary and 2 of Amerikaz Most Wanted with Snoop Dogg before dissipating into thin air, leaving the audience in awe, and somewhat unsettled, by the technology used to make the rapper reappear and perform.