Before he was a four-time World Series champion, five-time All-Star, and four-time Gold Glove winner with a certain baseball powerhouse in the Bronx, Bernie Williams went to a performing-arts high school. On a late-summer day, the 57-year-old Puerto Rican recalls his time at Escuela Libre de Música in San Juan with fondness. He still keeps in touch with former classmates, the years spent alongside them cementing music’s place in his life forever. But at 16, Williams was on a very different path from peers who would go on to become professional musicians, enter conservatories, or form a band or two: He signed with the New York Yankees, a decision that would lead him to become a generation-defining center fielder.

“Not a lot of people in high school knew that I was playing sports on the side,” he says in his mellifluous voice. “So [it was] to their huge surprise when they saw me for the first time in 1991 playing for the New York Yankees. And it’s like, “Was that the same guy?’ ”

You may have asked that very question had you seen Williams on stage in Brooklyn’s Prospect Park this past summer, performing original compositions with the New York Philharmonic. But music has underscored the former Bronx Bomber’s journey from the beginning, its duet with sport carrying him to serious success in two disciplines that seem impossible to align. Among his numerous other accolades, he has more postseason R.B.I.s (80) than any other player in Major League Baseball history. He earned a Latin Grammy nomination for his second studio album and holds a bachelor’s degree in jazz performance. He has played with everyone from Paul Simon to Bruce Springsteen to Twisted Sister. And he’s not done yet.

Williams remembers the first time he picked up a guitar. He was 8—around the same age he picked up a bat. His father, Bernabe Sr., a merchant marine, had taught himself how to strum a few Puerto Rican tunes on a guitar he’d brought back from Spain and began to teach his son. From there, the younger Williams was hooked, enrolling in weekly lessons with a neighborhood music teacher. Those sessions eventually led him to Escuela Libre de Música, a 45-minute drive from home. As his classical-music skills grew, so did his athletic ability: He was excelling in youth baseball, too. For the Williams family, balancing such different pursuits wasn’t unusual. “My mom really had this sort of mindset that she wanted us in a lot of things when we were kids, to have the opportunity to raise us more well-rounded,” he says.

Then the Yankees came knocking in 1985, and everything changed. But while his career on the diamond skyrocketed, music stayed fast by his side—especially in those early days in the minor leagues, when Williams wasn’t yet 21 and couldn’t properly hit the town. “My guitar was my companion for all those years,” he says. Continuing with both music and baseball wasn’t really a decision; the two came as naturally as breathing, and the symbiotic relationship unfolded easily before him. (Williams’s first book, Rhythms of the Game, is an ode to this very topic.) Timing, for instance, is paramount; playing the right note at just the right moment can “pierce someone’s heart or spirit,” he says. That phenomenon bleeds into baseball as well: The miraculous split second when the ball meets the bat over home plate creates its own kind of symphony. Both also demand total discipline, a rigor that requires deep understanding of every nuance. And, of course, both invite failure—often in public, with everyone watching. “When you’re playing a tune and you clunk a note, you can’t dwell on that, ’cause you still have the rest of the music to play… and if you drop a fly ball, if you strike out, if you don’t produce when it’s a clutch situation, you can’t dwell on that,” Williams explains. For him, it was never baseball versus music; it was both, together, that made him excel.

That dance between the two worlds reached its peak in 2003, when Williams dropped his first album, The Journey Within, while still playing for the Yankees; he recorded it during the offseason. There was the time when he played a day game in Toronto, then hopped straight on a plane to Chicago to perform that evening. Most of the album’s compositions, a mix of jazz, rock, and Latin influences, were created by Williams himself. His second album, Moving Forward, from 2009, arrived post-retirement. “I was more savvy. I had a little bit of a better idea of what I wanted the sound to be like,” he says. The collection nabbed him a Latin Grammy nom for best instrumental album, a high-water mark in his musical career.

After baseball, going back to music school was a no-brainer. “I wanted to be able to play with everybody, everything… be trained in a way that I can understand the language of music [that] will enable me to be in a more successful position where I could actually do these things,” he explains. So, at the age of 45, Williams enrolled in the Manhattan School of Music, where he studied for his Bachelor of Music in jazz performance. His fellow students were largely unaware of his baseball stardom. “You know, ‘Who’s that old guy in the back, telling them not to erase the board ’cause he can’t see stuff from that far away?’ ” Williams quips. It was as if his time in the pinstripes never happened. “I had to prove myself that I could hang out with them. So it was a really humbling experience, you know, saying, ‘None of the home runs I hit, none of the World Series rings—none of that stuff was going to help me now.’ ”

Williams graduated in 2016, and new doors opened in the music world. Perhaps most notably, he joined a Philharmonic performance with famed conductor Gustavo Dudamel at Lincoln Center, where his original compositions were transformed into classical orchestral arrangements—a process Williams says gave him a great tapestry of colors to play with. This January, he’ll grace another major stage, performing at Carnegie Hall alongside internationally renowned operatic tenor Jonathan Tetelman in a program showcasing multiple genres.

“There’s nobody like Bernie—there really isn’t,” says Richie Cannata, the famed saxophone player who has worked as Williams’s musical director. “You could tell this guy to be a doctor tomorrow, and by the end of the new year, he’d be a doctor.”

Music has also given voice to a cause close to Williams’s heart: raising awareness of interstitial lung disease, specifically idiopathic pulmonary fibrosis (I.P.F.)—the illness that claimed his father’s life. The chronic condition makes breathing increasingly difficult as scar tissue and inflammation build in the lungs. His most recent campaign, Tune In to Lung Health, features a series of videos demonstrating musical breathing exercises—developed by famed vocal coach Eric Vetro, who has worked with Ariana Grande, John Legend, and more—to improve respiratory function.

Williams has other passions, too. Thanks to modern medicine—he has had both shoulders replaced in recent years, among other procedures—he has taken up hobbies once off-limits because of baseball’s wear and tear. Now he skis, rides motorcycles, and putts on the golf course. Music, though, remains front of mind: Williams is at work on his next album, hoping to strike a different chord by drawing on his studies at the Manhattan School of Music. “I’m not going to try to change who I am as a person or as a musician,” he says, “but I think [this next album] might be a little bit more complex or daring.” Still swinging for the fences. 

Top: Former New York Yankees star center fielder Bernie Williams is also a well-regarded composer and guitarist. Here, he performs at the Sheen Center in New York City.