Yunchan Lim’s victory at the Van Cliburn International Piano Competition last year made him a sensation. He says the attention makes him uneasy.After six hours of sleep and a breakfast of milk and curry rice, Yunchan Lim, the South Korean pianist, was in a rehearsal studio at Lincoln Center on Tuesday morning working through a treacherous passage of Rachmaninoff.“A little bit faster,” Lim, in a black sweatshirt and sneakers, said casually to the conductor, James Gaffigan, as they prepared for Lim’s New York Philharmonic debut this week. Gaffigan laughed.“Usually pianists want the opposite!” the conductor said.Lim — shy, soft-spoken and bookish — stunned the music world last year when, at 18, he became the youngest winner in the history of the prestigious Van Cliburn International Piano Competition in Texas. His victory made him an immediate sensation; a video of his performance of Rachmaninoff’s Piano Concerto No. 3 in the finals has been viewed more than 11 million times on YouTube. (He will play that piece with the Philharmonic this week, under Gaffigan’s baton.)Still a college sophomore, Lim has inspired a devout following in the United States, Europe and Asia. He has become a symbol of pride in South Korea, where he has been described as classical music’s answer to K-pop. Like a pop star, his face has been printed on T-shirts.Lim at the Van Cliburn competition, playing with the Fort Worth Symphony Orchestra.Richard Rodriguez/The Cliburn, via Associated Press“He’s a musician way beyond his years,” said the conductor Marin Alsop, who headed the Cliburn jury and led the Rachmaninoff performance. “Technically, he’s phenomenal, and the colors and dynamics are phenomenal. He’s incredibly musical and seems like a very old soul. It’s really quite something.”But Lim is uneasy with the attention. He does not believe he has any musical talent, he says, and would be content to spend his life alone in the mountains playing piano all day. (He limits his use of social media, he says, because he believes it is corrosive to creativity and because he wants to live as much as possible as his favorite composers did.)“A famous performer and an earnest performer — a true artist — are two different things,” he said in an interview this week at the Steinway factory in Queens, where he was shopping for a piano.Born in Siheung, a suburb of Seoul, Lim had a childhood filled with soccer, baseball and music. He began studying the piano at 7, when his parents enrolled him in a neighborhood music academy. He was drawn to the piano, he said, because he had grown up hearing Chopin and Liszt on recordings that his mother had purchased when she was pregnant. He was also taken by the majesty of the instrument.Lim was taken by the majesty of the instrument when he was young. “The grand piano looked shiny and most impressive,” he said.Ayesha Malik for The New York Times“Technically, he’s phenomenal,” Alsop said of Lim, “and the colors and dynamics are phenomenal.”Ayesha Malik for The New York Times“The grand piano looked shiny and most impressive,” he said.At 13, he enrolled in a prep school at Korean National University of Arts in Seoul. His teacher, the pianist Minsoo Sohn, was impressed by the sensitivity of his interpretations.“At first he was a little bit cautious, but I immediately noticed that he was a huge talent,” he said. “He’s very humble, a student of the score and he isn’t over expressive.”Sohn initially steered his student away from competitions, worried about the pressure. But when the pandemic delayed the Cliburn competition, which is held every four years, making it possible for Lim to qualify, Sohn suggested he give it a try, telling him to treat it as a performance, not a competition.“I thought the world needed to listen to what Yunchan could play in his teenage years,” Sohn said.When Lim arrived in Fort Worth for the competition, which took place over 17 days, he said he felt the spirit of Van Cliburn, the eminent pianist for whom the contest is named.Lim sometimes practiced as much as 20 hours a day, he said, sending recordings to Sohn, who was in South Korea, for guidance. He existed on a diet of Korean noodles and stews prepared by his mother, who had accompanied him, as well as midnight snacks of toasted English muffins with butter and strawberry jam made by his host family.“I knew it was like Russian roulette,” he said of the competition. “It could turn out well, or you could end up shooting yourself in the head. It was a lot of stress.”As he prepared to walk onstage to play the Rachmaninoff concerto, he said he thought of Carl Sagan’s idea of Earth as just a “pale blue dot” in the universe.“When the stage doors open and the audience applauds, when I nervously sit down at the piano and press the first key, that moment is like the Big Bang for me,” he said. “I’m nervous, but the image of the pale blue dot gives me courage. I just think of the moment as something occurring in that small little speck.”His Rachmaninoff won ovations, but he was dissatisfied with the performance, believing that he achieved only about 30 percent of what he had hoped to accomplish. Since the competition, he said he had been able to watch just the first three minutes of the YouTube video before growing dispirited.When he returned to South Korea after the Cliburn, he said he was unchanged. “I just want to say that there’s nothing different with me and my piano skills before and after the win,” he said at a news conference with his teacher.“I just want to say that there’s nothing different with me and my piano skills before and after the win,” Lim said at a news conference with his teacher.Ayesha Malik for The New York TimesLim, who is still enrolled at Korean National University of Arts, plans to transfer this fall to the New England Conservatory, in Boston, where Sohn now teaches.As a student, his international career has taken off, with a recital at Wigmore Hall in London in January and an appearance with the Tokyo Philharmonic Orchestra in February. This summer, he will reunite with Alsop to perform the Rachmaninoff concerto at the Bravo! Vail festival in Colorado and the Ravinia Festival in Illinois. Next year, he will make his Carnegie Hall debut with an all-Chopin program.The New York Philharmonic booked him soon after Deborah Borda, its president and chief executive, saw YouTube videos of his performances at the Cliburn — a Beethoven concerto as well as the Rachmaninoff.“I was blown away by how fluent he was in both styles,” Borda said. “He was just brilliant.”Ahead of his debut in New York, Lim has been fine-tuning his interpretation of the Rachmaninoff. In preparing the concerto’s somber opening notes, he said, he imagines the “angel of death” or cloaked figures singing a Gregorian chant, following his teacher’s advice.This performance is especially meaningful, he said. On his commute to and from middle school, he often played a 1978 recording of the Rachmaninoff concerto by Vladimir Horowitz and the Philharmonic. He said he had listened to the recording at least 1,000 times.Lim said he felt nervous to follow in the footsteps of Horowitz, one of his idols, and that he would always consider himself a student, no matter how successful his career might be. He said artists should not be judged by the number of YouTube views they received, but by the authenticity of their work.“It’s a bit hard to define myself as an artist,” he said. “I’m like the universe before the Big Bang. I’m still in the learning phase.”“I’d like to be a musician with infinite possibilities,” he added, “just like the universe.”Jin Yu Young contributed research from Seoul. More