Last weekend, at Coachella music festival in California, Snoop Dogg was joined on stage by Tupac Shakur, one of the most famous rappers from the 1990s. Tupac, who has spent the last fifteen years dead, was able to ‘appear’ through the clever use of some technological trickery. The stunt was manufactured by AV Concepts (the same company responsible for the stunning aging effects in hit movie The Curious Case of Benjamin Button) and took over four months to prepare for just two songs. The rapper performed Hail Mary and two of Amerikaz Most Wanted before disappearing in a bright flash of light.Regardless of how you feel about Tupac's music his recent reanimation is spectacularly morbid. Credit where it's due, the surprise performance was well received by the crowd and by fans online, and while it was undoubtedly a gimmick, it was definitely an entertaining gimmick.What does this bizarre zombie performance say about live music itself? Can a meticulously crafted pre-approved hologram really be considered "live" in any sense? Is Tupac's appearance at Coachella credible when it is comprised of nothing but a projection, a pre-recorded song and a convincing impressionist asking “What the f*ck is up Coachella?”. It worked for Gorillaz, performing with a mixture of live musicians and holograms, embracing the artificiality of a cartoon band, but can that work for every artist? You could argue that Top of the Pops did the same for decades, where artists on the show were given no option but to mime along to a backing track, but it's probably not the same when an artist is co-opting the popularity of a dead contemporary.It certainly isn't the first time we've seen the music industry capitalise on the potential for profit in exploiting the deceased. Hours after the death of Whitney Houston Sony music hiked the prices of the late singer's greatest hits (although when challenged Sony claimed the original pricing was an oversight). With that kind of philosophy there's no doubt this technology will be pursued if it becomes profitable.Dre insisted this was a one-off, but given both the financial success of the venture as well as the PR generated for the stunt, it's only a matter of time time until we see a host of musicians in high profile posthumous performances, unknowingly tarnishing their own legacies from beyond the grave. Perhaps this is just another step forward in technology that will eventually become the norm. Similar technology was used to entertain Simon Cowell with a hologram of Frank Sinatra. Dre was involved in talks about a potential Tupac tour, and expressed interest in the possibility of a holographic performance of Jimi Hendrix – an artist famous for his passionate live performances.Maybe it's time for Michael Jackson to finish his ‘This Is It’ tour. Philip McFaddenImage credit - AndreLucian.