Have you been getting a kick out of Coachella's jams and arts in Indio, California? Or, did you decide to peacefully enjoy it from home via YouTube's site? Either way, you may have heard Tupac made an on-stage holographic appearance over the weekend, performing Hail Mary and 2 of Amerikaz Most Wanted alongside Snoop Dogg. Tupac's hologram was made possible by AV Concepts in partnership with Dr. Dre's production company, after reportedly working on the project for a few months. The outfits used a di