In 2012, at Coachella, Snoop Dogg and Dr. Dre were on stage amazing an already amped up audience when, suddenly, they were joined by a long dead colleague. Tupac Shakur, brought to life by a $100,000 light show, was the talk of the internet for days. The impact of Tupac's virtual resurrection had the potential to be massive. It wouldn't just change music or live shows. It had the potential to impact all forms of entertainment.