After Tupac returned from the dead as a supposed hologram at Coachella, the music industry has begun to weigh up the financial benefits of bringing artists back from the dead.
But is it morally right to exploit the image of an artist when it is impossible to get their consent?
First, let's explain the how this admittedly impressive technology works. It was actually invented by Henry Dircks in 1862, and was later used to make a ghost-like figure appear as a reflection on an angled pane of glass. As long as the audience doesn't know about the pane of glass, they see a semi-transparent person. The technique was called "Peppers Ghost" - see the explanation video below and it'll all make sense.
For Coachella, a CGI version of Tupac (most likely an actor being captured by motion technology, the re-created with computer graphics) was projected onto a special fabric called Mylar. Putting issues of integrity aside, it's a very cool idea and looks incredible.
But what does it mean for the music industry? Will we see Jimi Hendrix rocking again? Will The Beatles reform? In fact, there are already reports that Michael Jackson will tour with the Jackson Five.
Let's hope that secret project between the surviving Nirvana members and "Nevermind" producer Butch Vig is nothing to do with a Kurt Cobain hologram.
As Classic Rock points out, technology has been making live shows easier to produce for years. The ability to lip-sync or auto-tune vocals has helped pop artists ensure their shows are consistent, but we could all argue that it's stifled the reality of live performance.
In Japan, this technology has been the norm for some time. A virtual artist called Hatsune Miku is a huge star, and she doesn't even exist. Of course, US acts like Gorillaz have been showed that fictional acts can be a success in the west too.
Maybe the so-called "holographic" performances will prove to be a good thing, but there's a very real risk that live music will become a cookie-cutting exercise where promoters simply email a performance around the world so that a band can play in five places at once and maximise revenue.
But let's not ignore the potential for artists to find inventive ways of using holograms. Ultimately, it will be up to the fans to vote with their wallets and ensure this technology is used for the right reasons.
Here's the original Tupac performance at Coachella this year:
Here's a video showing how the "Pepper's Ghost" illusion works - skip to 1:27 for the explanation:
X Japan were one of the first to use this technology in a musical setting, reviving their late guitarist Hideto Matsumoto in 2008. He had committed suicide in 1998:
And finally, here's the Japanese virtual artist Hatsune Miku. It's worth seeing just to witness the scale these productions can take. Notice the screen for her projection at 2:40:
What do you think?
Will holograms be a disaster for live music, or can you see past it and think up a creative use that will actually improve live shows?
And finally, how would you react to something like a Nirvana tour if it were announced? Let us know in the comments.