Right before India went into lockdown, on March 24, a magician named Karan Singh canceled all of his public shows and issued an invitation to his 42,000 Instagram followers. He would perform for free, over Skype, for anyone who contacted him. It could be one person, two people, 50, whatever. Book a slot and he’d appear in your home, virtually, for a 15-minute set.

“You don’t need advice on how to deal with coronavirus from a magician,” he said, wearing a black polo shirt and speaking earnestly, with a slight British accent, into his laptop camera. “But what you can get from a magician is entertainment.”

That was more than 400 shows ago. From his bedroom in New Delhi, Mr. Singh has spent roughly 12 hours a day, nearly every day, digitally performing card tricks and feats of mentalism all over India — the core of his fan base — as well as Canada, the United Kingdom, Sweden, Italy, Germany, Nepal, the United States, Mexico, Singapore, Australia and the list goes on.

A variety of artists, from musicians to chefs to dancers, have found ways to perform during the Covid-19 crisis. Most post their work on the web and beckon to the masses. Mr. Singh, a 28-year-old who studied acting in London and who typically plays corporate gigs and small theaters, has taken a more door-to-door approach. In part, the goal was self-preservation.

“I did it for my mental health, because I would have gone mad if I didn’t have an audience to perform for,” he said in an interview. “This just gives me an outlet.”

Mr. Singh recently allowed a reporter to join him online during a day of about a dozen performances, starting at 3 p.m. New Delhi time. One of the first stops was Kampala, Uganda, where a young fan named Ashay Shah was sheltering in place with his parents. They were joined online by Ashay’s sister, Bansari, who lives in Chicago.

“I’ve been following you since 2015, and I think I’ve watched all of your YouTube videos,” Ashay said. His favorite, he went on, is a video posted in 2018, in which Mr. Singh asks the captain of the India national cricket team, Virat Kohli, to think of the name of someone from his childhood, like a friend or a teacher. Drawing out the drama for maximum impact, and talking over the din of a lively party, Mr. Singh somehow divines the name. The video has been viewed more than three million times.

Mr. Singh calls himself a “psychological illusionist,” and his effects often straddle the line between magic and mind reading. He started his show for the Shahs by displaying a standard deck of cards, still in its cardboard box.

“Ashay, if I were to ask you to name any card in the deck, which card would you name?” Mr. Singh asked.

“The nine of spades,” Ashay replied.

“OK. Bansari, I want you to think of any number, up to 30,” Mr. Singh said.

“Twenty-five,” Bansari said.

“Twenty-five,” Mr. Singh repeated. “I have been holding this deck of cards. If the 25th card in my deck ends up being the nine of spades, that would be insane,” he said, chuckling giddily to underscore the improbability.

The Shahs grinned and agreed.

“Let’s give this a go,” Mr. Singh said, holding the box in full view of the camera. “Make sure I don’t do any sleight of hand.”

He emptied the box by tilting the cards into his left hand and then started flipping them over with his right, slowing down when he reached 22.

“Twenty-three, 24 and this,” he said, pausing for a moment before turning over the nine of spades, “is 25.”

The Shahs clapped. “Amazing,” said Bansari.

Mr. Singh, who started performing when he was 16, is accustomed to a wide range of reactions to his work, from glee to rage. At a club performance a few years ago, he guessed a spectator’s PIN, prompting the man to pull a gun, point it at his head and demand an explanation. (A bouncer interceded.)

What’s more common is for audience members to regard a trick as something akin to a crime in need of solving. They skip the awe and turn into detectives. On some level, the reaction is perfectly understandable. Magic acts are impossible without lies, and a magician is what you get when you mix a con artist with an entertainer. The difference is that the con artist wants to take (money) and a magician wants to give (a sense of wonder).

Because deception is part of the job, and transparency is out of the question, every magician must consider a very basic question: Who, exactly, do you think you are?

Starting in the 19th century, and through decades of vaudeville, the standard magician persona could be labeled “the astonishing butler,” a guy in a tuxedo whose dress conveyed gravity and prestige.

David Copperfield shed much of that formality, added Las Vegas glitz and presented as a lanky mystic. David Blaine would later ditch every vestige of showmanship, including a stage, and performed seemingly improvised miracles for strangers on the street. “Dead-eyed shaman in a T-shirt” has been the most influential character in magic for more than 20 years.

Mr. Singh has something of the casual-wear wizard about him, minus the solemn intensity. When he laughs as an effect unfolds, he is anticipating the delight of his crowd, as tickled as anyone. He didn’t get into magic with riches in mind — though when the pandemic started, he had saved enough money to work gratis for weeks. (He realized recently that people are willing to pay for live, online entertainment, so in the last few days, he has started to offer scheduled, 45-minute Zoom shows. A ticket costs about $5 per household.)

An hour or so later after his performance in Uganda, Mr. Singh “appeared” in Tipperary, Ireland, where he performed for sisters Diane and Breda Lanigan. At one point in the show — while holding up a wristwatch for unexplained reasons — Mr. Singh asked the women, both in their 50s, to describe a notable moment in their past that they would both remember.

Usually, this takes fewer than 10 seconds. Not with the Lanigan sisters. “Maybe fighting over a doll at Christmas,” Breda suggested. “She got the doll and I got the pram. A pram isn’t much fun without the doll, I can tell you that much for nothing.”

Diane had a better idea. “We took a road trip to Florida when I was living in Arkansas, in my 20s,” she said. “We were out, the two of us, trying to hook up with these two fellas in a club, right? And halfway through the night, Breda decided she was fed up with her fella and she said she wanted to switch. I said, ‘But I kind of like my fella.’ And she said, ‘You’ll like the other guy, too.’”

When the sisters stopped laughing, they noticed the watch Mr. Singh had been dangling, its face turned away from them. What time did this road-trip fella switch happen, he asked?

“It was about 11:30, in the back of a car, because the club had closed,” Diane said.

“Before I asked you a single question, I started holding this watch,” he said. He knew the pair would relive this particular memory before he called them on Skype, he said. And he further knew that this memory unfolded at 11:30. To prove it, he turned the watch face around and showed the time.

It was 11:30.

The Lanigans smiled. Breda squinted, got closer to the camera and launched a brief, lighthearted inquisition.

“Are you sure you don’t have a watch winder on the top of that watch?” she said, cackling. “Are you sure?”

Mr. Singh showed her the buckle at the top of the watch, which looked utterly conventional.

“No,” he said. “That’d be a smart way to do it, though.”

He found a more receptive audience a few hours later in San Diego. Barry Edelstein, who runs the city’s Old Globe Theater, and his seven-year-old son, Auggie, were happily dazzled after each trick.

“You need to go to Washington and fight the coronavirus,” said the elder Edelstein.

The performance ended with Mr. Singh asking the Edelsteins to guess the four-digit passcode to his own iPhone. First he demonstrated that a random set of numbers wouldn’t work. Then he asked father and son to name numbers between zero and 9, one at a time.

Together, the pair came up with 4097.

“Now you could have come up with any numbers, you could have come up with any order that you wanted,” Mr. Singh said with a grin, holding his iPhone screen up to the camera. He’d already entered three of the four numbers, in plain view. “Make sure my hand doesn’t go anywhere near the home button because I don’t want you to think I’m using a fingerprint for this.”

He pushed the final digit. The iPhone unlocked.

“Man,” the elder Edelstein said. “That is spectacular.”

Next to him, Auggie put his hands to either side of his head, then opened his fingers as he moved his hands outward. It was the informal, international sign language for “You just blew my mind.”