I met Ronnie James Dio once, when he was alive. Tenacious D, the parody band that gave Jack Black his start, had recorded a gently mocking tribute song called “Dio,” in which Black demands Dio’s cape and scepter and informs him that he’s too old to rock (“no more rockin’ for you!”). Dio had been a good sport about the whole thing and agreed to make a cameo in the Tenacious D movie, which premiered in 2006 at Grauman’s Chinese Theater. I remember standing around the after-party, nursing a drink and feeling awkward, when I spotted Dio, chatting in a corner of the ballroom with his wife. I decided to introduce myself. He was quite short, even for a celebrity, and exceedingly gracious. He told me Black had personally called to pitch the film, insisting that they wouldn’t make the movie unless he agreed to “play the part of Ronnie James Dio.” Smiling, Dio continued, “Then he said: ‘Well, we will make the movie. But it’ll be [expletive].’ ”

Across town in Marina del Rey 13 years later, I sat in the office of Eyellusion’s creative director, Chad Finnerty, as he digitally manipulated a photorealistic 3-D image of Dio’s face. Finnerty grew up in Pennsylvania with dreams of becoming a Disney animator — old-fashioned cell animation, like what they did on “Snow White and the Seven Dwarfs” — but by the time he graduated from college, the world had gone digital. He spent years working as a C.G.I. animator at Digital Domain, on movies like “Flags of Our Fathers” and “Pirates of the Caribbean: At World’s End.” When Jeff Pezzuti, a Westchester-based vice president of finance at a cloud-computing consulting firm, decided to start his own hologram company, Eyellusion, he reached out to Finnerty, asking if he wanted to talk. Pezzuti loved heavy metal — he wore a Dio T-shirt for his seventh-grade class picture — and after seeing the Tupac hologram, he wondered, “Can we do something like that in the rock world?” Eyellusion has since received a $2 million investment from Thomas Dolan, whose family owns controlling interests in Madison Square Garden and AMC Networks and whose father founded the New York-area cable-television giant Cablevision.

Finnerty supervised the creation of the Zappa and Dio holograms for Eyellusion. “I’m a bit rusty with this program,” he apologized, pecking at his desktop keyboard. Soon a hideously lifelike digital rendering of Dio’s face appeared on a large-screen monitor hanging on the wall. For a moment, it bobbed in front of a black backdrop, which made me think of the old “Charlie Rose” set. I briefly thought about pitching a “Black Mirror” episode in which a Charlie Rose-type character interviews the cryogenically preserved heads of rock stars. “We collected all of our data in 2017,” Finnerty explained. That’s when they filmed the body double and did the facial capture, is what he meant. During the facial capture, hundreds of eye, mouth and facial-muscle movements of a living subject (not necessarily the body double) are recorded. Imagine a puppeteer, Finnerty said, only with thousands of puppet strings to manipulate.

He clicked his mouse, manipulating a digital lever on the screen, and “Dio’s” eye suddenly, eerily shifted to the left. You couldn’t do this two years ago, Finnerty went on, moving another lever. “Dio’s” eyes shifted right, up, down. Finnerty said he had done lots of work on “The Walking Dead,” but that was forgiving, because it’s zombies. Having a person look real while performing a song for six minutes, with no cutting away or other editing assists that would be available in a film or television show, that was something else entirely.

“Dio” winked, puckered his lips, raised an eyebrow.

I stared at the image’s mottled skin, textured and painted with a level of detail down to the pore. “Hair simulation is the most difficult part of the entire process,” Finnerty said, adding, “My hair guy is also my fire, water and ice guy.” His lighting team had done the skin. Had Dio submitted himself to a full-body scan while alive, the process would have been much easier. Finnerty thought it would be great if more living musicians and actors were proactive about being scanned. Any actor who has starred in a movie involving significant amounts of C.G.I. has already been scanned, he pointed out.

The more bullish hologram boosters envision all sorts of uses beyond the second coming of music deities major and minor. Finnerty just made a hologram for the Ronald Reagan Presidential Library of the former president. Prime Minister Narendra Modi of India has campaigned holographically, and a circus in Germany uses holographic projections of elephants and horses instead of live animals. Base, meanwhile, has cut a deal with Jack Horner, the paleontologist who served as a scientific adviser for “Jurassic Park,” to create dinosaur holograms that will travel to natural-history museums. Imagine, Becker said, a dialogue between holograms of Abraham Lincoln and Martin Luther King Jr. Or a Julia Child hologram teaching a cooking class. Or a Derek Jeter hologram teaching you how to bat.