Concert experiences headlined by simulations instead of live artists have captured the public imagination. Tupac Shakur's posthumous appearance at California's Coachella Festival back in 2012 is a cultural touchpoint to this day. Audiences have been flocking to the ongoing ABBA Voyage experience in London since it debuted in May 2022. And there's been lots of chatter over the past couple of months about the forthcoming Elvis Evolution.
Scheduled to launch in November, Elvis Evolution will employ the latest in machine-learning technologies to reanimate the late King of Rock 'n' Roll. But this show — as well as many other so-called "hologram" stage productions featuring dead or absent musical celebrities — also make use of many longer-standing technologies, including a magic trick that's nearly 200 years old.
Don't say 'hologram'
The first thing to clear up about these types of virtual performers is that, technically speaking, none of them are holograms.
"Holograms are actually three-dimensional still images created by laser technology, like the security icon on a credit card," said Paul Debevec, a research professor in computer graphics at the University of Southern California's Institute for Creative Technologies.
Debevec said we can blame a little sci-fi movie made back in 1977 for the word's misuse.
"If you watch the movie Star Wars, they use 'holograms' to mean a person suspended, floating in space," said Debevec, referencing a well-known moment from the original 1977 film, in which the droid R2-D2 plays a recorded video message of Princess Leia asking for help.
"The whole 'Help me, Obi-Wan Kenobi' effect, that certainly captured the popular imagination," Debevec said.
The making of AI Elvis
So if the theatrical reincarnations of Elvis and his ilk aren't holograms, what are they?
Andrew McGuinness is the CEO and founder of Layered Reality, the London-based company behind Elvis Evolution, as well as two other high-tech immersive experiences currently running in London – The War of the Worlds and The Gunpowder Plot.
According to McGuinness, the technology for putting The King back on the concert stage can essentially be broken down into two parts.
"First of all, how we will create the content," McGuinness said. "And that's where the AI comes into it."
McGuinness said his company acquired the global rights for the creation of an immersive entertainment experience based upon Elvis and his story, and as a result is feeding all sorts of material from the star's official archives — hundreds of hours of video footage, photos, music — into a computer model.
This model effectively learns in minute detail how Elvis sings, talks, dances and walks.
"So, for example, if a performance of Elvis was originally shot from the front, we will be able to show you a camera angle from behind that was never actually shot," McGuinness said.
An old trick
The second part of the process involves delivering this AI Elvis in a way that will make him seem real to live theater audiences. That's where a slew of other technologies, including an old stage trick called Pepper's Ghost, come in.
"I think audiences would be surprised, going to see these 'state of the art' displays, that what they're looking at is something from 1862," said Jim Steinmeyer, a designer of stage illusions who also writes books about magic history, including one about Pepper's Ghost.
"It was used to put a three-dimensional ghost on stage, interacting with actors," Steinmeyer said, adding that the Victorian trick originally involved an actor dressed as a ghost hidden beneath the stage. "And then an angled piece of glass at the front of the stage would let you see the actors on the stage. But it would also work to reflect the actor that was concealed."
British engineer Henry Dircks first came up with the concept.
"It should have been called Dirck's Ghost," Steinmeyer said. "And Dircks was bitter about that for many, many years."
But Steinmeyer said scientist John Henry Pepper, a P.T. Barnum-like figure who created elaborate, crowd-pleasing public lectures in London, turned Pepper's Ghost into a truly workable system.
"It was a scientific novelty, but it was a kind of fantastic visual success," Steinmeyer said. "Since then, it's been used in many different forms."
Outside of concert settings, this old illusion has shown up in all sorts of places.
Among them, the 1931 movie romance Daddy Long Legs, in which a rich old man is haunted by visions of a young orphaned woman; the 1980s arcade video game Asteroids Deluxe; and, perhaps most famously, the Haunted Mansion attraction at Disneyland, where spectral figures play the organ and waltz across the ballroom. A version of the technology has also been used in "heads-up displays" in cars.
Technology isn't the most important thing
Layered Reality's McGuiness said he's excited to bring together many old and new technologies for Elvis Evolution. But ultimately, he said, it all needs to be in service of the audience's emotional journey.
"What I dream about is for people to forget about the technology in its entirety," McGuinness said. "I want them to feel like they've really seen Elvis perform."
Audio and digital story edited by Jennifer Vanasco; audio produced by Isabella Gomez Sarmiento; web produced by Beth Novey.
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