On a balmy Friday night in mid-March, in a little conjunto club in San Antonio called Saluté International Bar, Juanito Castillo was attempting a reintroduction of sorts. Most of the audience was familiar with the 22-year-old performer, blind since birth. He’d been playing around town on multiple instruments since the age of 5, and the middle-aged couples in the audience had seen him perform many times right there, on the tiny corner stage bathed in pink neon light.

But Castillo’s latest band, Inovación, was new to his listeners: As their reverent whispers made clear, they knew him primarily as the anointed protégé of conjunto master Esteban “Steve” Jordan, a wild man of the accordion who died of liver cancer last August. A long-haired pachuco hipster who wore a snakeskin eye patch and puffy pirate sleeves, Jordan began making a name for himself in the sixties, when he pushed the limits of his instrument by using phase shifters, fuzzboxes, and Echoplex effects. Known for juxtaposing blues, jazz, Latin rhythms, zydeco, country, rock, and pop with traditional polkas, cumbias, and waltzes, Jordan earned a Grammy nomination in 1987 and was widely hailed as the Jimi Hendrix of the accordion. “I play the jazz accordion,” he once said. “Anytime the young players want to play modern, they come my way.”

This is exactly what Castillo did. Starting at age fifteen, he played drums in Jordan’s backup band, El Rio Jordan, and five years ago, when Jordan got sick, he started filling in as the front man. Though Jordan had told local music writer Hector Saldaña, “No hay nadie que me puede copiar” (“There’s no one who can copy me”), he happily extolled Castillo’s talent, a habit that must have stunned those familiar with Jordan’s typical appraisals. This, after all, was the man who once told Carlos Santana his guitar playing was substandard and scolded Linda Ronstadt for singing off-key; giving and receiving praise was not his forte. “I’m working for me,” he told the San Antonio Express-News in February 2010. “If they don’t like it, ‘[Expletive] you, brother.’ I don’t give a [expletive].” He told people that he knew only two geniuses. One, of course, was himself. The other was Juanito Castillo.

For more than twenty years, Jordan had played at Saluté almost every Friday. Now Chicano filmmaker Efrain Gutierrez stood up before the crowd and spoke loudly. “Juanito Castillo has been asked to play Conjunto Fest, which is a great honor,” he said, referring to the annual weekend of music concerts held every May, which attracts around 10,000 people. “We thought we’d sell some tickets and buy him a Steve Jordan accordion.” The audience nodded earnestly. “Originally, I thought this would be easy. ‘What would it cost,’ I thought, ‘a few hundred dollars?’” He stopped and rolled his eyes. The custom-made Steve Jordan Rockordeon—a modified squeeze box with fast-action buttons, first designed by German manufacturer Hohner for Jordan himself—cost $2,400, a number that translated, at $5 a head, into 480 tickets. The tiny venue, which appeared to be half full, was about 440 tickets short.

Still, if the club’s twelve-foot-tall shrine to Jordan was any indication, the attendees were determined to keep the master’s legacy alive by promoting his pupil, now stepping out from behind his predecessor’s large shadow. The moment Gutierrez spotted Castillo entering the bar, he stopped short and announced, “Juanito’s in the house!” As Castillo waved his lanky arm and walked onto the stage, club owner Azeneth Dominguez, who was Jordan’s companion for his last eight years, watched with a smile from behind the bar. “I’ll tell you,” she confided, “I’m being selfish. I have high hopes. I want him to fill the void for Esteban. I want to hear that sound again.”

Any musician hoping to find a home in a genre must strike a balance between tradition and innovation. So it has been with conjunto. It began in the 1800’s as creative tinkering: German settlers introduced the accordion to South Texas Latinos, who combined it with traditional instruments of northern Mexico. But by the mid- to late forties, the classic conjunto configuration was established—accordion, bajo sexto, bass, and drums—and the tempo was expected to be slow and danceable. Adhering to these standards helped a conjunto player court a following, but it also presented an artistic conundrum: Notable musicians don’t just master a tradition, they anticipate an audience’s unarticulated cravings and add twists. Legendary front man Valerio Longoria, for example, introduced vocalists in the fifties, and Jordan introduced his sound effects a decade later. Though these changes were eventually embraced, they did not come without risk.

For Castillo, who is so well versed in Jordan’s songs that he could earn a living performing only covers, the master’s passing puts him at a crossroads. Breaking with a legendary predecessor is nothing new (Ray Charles mimicked Nat King Cole until he cooled to the comparison; Ernest Tubb aped Jimmie Rodgers until a tonsillectomy changed his voice), but making original music hardly guarantees applause or paychecks. In his first months apart from Jordan, it became clear that Castillo had inherited more than a legacy. He had also inherited the possibility that his own name might be eclipsed.

One late afternoon, I went to San Antonio to meet Castillo in the spare, makeshift studio behind the house he lives in with his parents. He spoke of his career’s unusual beginnings and his present trajectory in a low, raspy voice while smoking his first of several joints for the evening. Castillo is pale, keeps his eyes closed at all times, and opens his mouth wide when he laughs, which is often. Given that he had just woken up around four o’clock and was hungover from a Spurs game after-party, he was remarkably amiable, charitably tolerating questions about his childhood—how he’d learned guitar from his father at age three, then took to drumming on kitchen pans and tinkering with a toy accordion, working his way up to fourteen instruments. These were stories he had told before, and they were distant enough to seem unremarkable to him. At the mention of Jordan’s name, however, he leaned forward and spoke with the wonderment of a kid who had encountered a magical alien.

“I met him when I was eleven,” he said. He had heard some of Jordan’s hits, like “La Polka Loca” and “Corrido de Johnny el Pachuco,” on the radio and asked his father, George, to arrange a visit to Jordan’s home studio. “I wanted to see the eccentricity behind the genius,” he went on. “Not how he did it. He was not going to show me how. I just wanted to get a little vibe, a little feel for what the hell he was—this short, skinny action figure with long-ass hair.” Whether Jordan was motivated by empathy for a young musician who, like him, suffered a visual impairment (his trademark eye patch covered a blind right eye) or the desire to indulge a fan, he accommodated the request. He also let Castillo stay for an entire day, allowing him to run his curious hands over the smooth guitars, the synthesizers, the reel-to-reel recorders, even the Rockordeon. For a youngster who was mastering a new instrument every few months, it was a thrilling experience. “He actually walked out to go play pool with Dad and let me be inside his studio,” Castillo said. “How many people would do that?”

Jordan’s generosity was rewarded. Two years later, when his regular drummer canceled just hours before a gig, a round of panicked phone calls determined that there was one musician in all of San Antonio available to fill in: thirteen-year-old Juanito Castillo. Never mind that the kid had heard Jordan play live only once. Never mind that he owned only one of Jordan’s thirty-some albums. “My reaction was to grab my sticks and get the hell down there,” Castillo said. “You don’t let the genius down.” A few beats into the first song, the teenager tapped out a two-second lick, prompting Jordan to turn around and holler, “Oh, hell yeah!”

“I would drum with them off and on after that,” Castillo recalled. By then, the backing group comprised Jordan’s sons Richard, on bass, and Steve III, on guitar, both of whom Jordan had also taught to play. Jordan began to take Castillo under his wing, inviting him out after the shows for a critique; he’d tell Castillo what he liked, what he didn’t, and what he wanted, dissecting each piece. “We were like two nerds,” Castillo said. “He’d get after you in music. ‘It’s like this!’ he’d say. ‘Move your hand with a circular motion!’ He’d give you the works. He made you do it over and over till you got it right. Could be two times, could be twenty.”

For a hard-living musician, he also offered surprisingly chaste advice. “Sometimes I’d be up all night and he would worry because I wouldn’t be getting my sleep,” Castillo remembered. The late nights became more frequent in 2007, when Castillo dropped out of high school and joined El Rio Jordan as a full-time member, eventually switching to keyboards. “We talked pretty much every day,” Castillo said. “‘You’re gonna get old too fast!’ he told me. ‘You need to slow down! You got a lot of stuff to do in your life!’”

Even as he was spending time with Jordan’s band, though, Castillo was developing his own career. He had been composing music since age eight and had released two CDs on the accordion with various players around town who’d been drawn to his talent. He didn’t lack encouragement, either. He was championed by his old accordion instructor, Bene Medina, a venerated local talent who had given Castillo formal lessons when he was nine. “I predict you’re going to be the greatest accordion player that comes out of San Antonio,” he’d told him. Like Jordan, Castillo added modern styles like rap and metal into the mix; lyrically, the music reflected his personal experiences. He called it “the diary.” “The diary keeps going,” he told me. “Never ends until I die and someone writes my biography.”

It’s difficult to imagine Jordan discouraging such presumptuousness, especially since the legend bestowed the ultimate compliment: When he was diagnosed with liver cancer, in 2006, and the sets became more grueling, he began occasionally handing the reins to Castillo. “We’d be smoking,” Castillo said, “and he’d ask me real casually to sit for him for a set. ‘Hey, bro, want to pick up the box?’ And I’d say, ‘Sure, why not?’” By February 2010, Castillo was having to fill in for the entire show, a lucky break that also raised a dilemma. “I had to keep it as Steve Jordan as I could,” he said respectfully. He paused, then added softly, “With a little hint of 2058.”

In August, Steve Jordan was alone with Dominguez and Castillo as he lay dying in his home. Jordan held his student’s hand. “Juanito told him not to worry,” said Dominguez. “He’d continue his legacy. And Steve left.”

In the obituaries following Jordan’s death, much attention was paid to his “eclectic” sound, his contributions to American music, his need to push the envelope. The San Antonio Express-News, which called him “the defiant, genre-defying accordionist,” quoted Jordan’s son Steve III declaring that Jordan’s work would endure through El Rio Jordan. “Just to follow in my dad’s footsteps is a big challenge for us, to carry that name,” he said. “But we’re the only ones that can do it. My father, he prepared us.”

Exactly what it meant to follow in Jordan’s footsteps—as Castillo himself had promised—was unclear. What, after all, does one preserve: a legend’s philosophy of innovation or the musical notes as he recorded them? While Jordan’s sons played the songs straight, Castillo improvised. “I tried to hang around his boys a little bit afterward, but egos are egos, and there’s nothing you can do,” Castillo told me with a shrug. “It got controlling. ‘You have to play like this.’ ‘You have to play like that.’ Not play a different way. What I had to play with Rio Jordan was vintage Steve Jordan, not modernized Steve Jordan. They called it ‘doing justice to the music.’” (My phone calls to Steve III were not returned.) Castillo last spoke to the Jordan brothers in October or November. “I went in and got my clothes and my glasses, and that’s it.”

In the handful of times that his new group, Inovación, has performed in clubs since forming last November, the band’s set list could best be described as eclectic, as apt to include a Jordan cover or a classic David Lee tune as a jazz improvisation or a George Strait hit. It is unclear whether Castillo’s direction will please Jordan fans. “I’ve heard a bunch of his new music,” said Joe Treviño, the owner and chief engineer of San Antonio’s Blue Cat Studios. “It leans toward the avant-garde. Really out-there.” Descriptions like these—the kind that would send a music promoter reaching for his Tums—please Castillo greatly. “Music has gotten so commercial we’ve forgotten that what sold us in the first place was originality,” he said. “If it sounds like radio, you’re screwed.” When I remarked on the obvious marketing hurdle before him, he fell back into his couch and stretched. “I want someone trying to market me to have as much trouble as they can,” he said.

Back at Saluté, Inovación swerved from jazz and polkas and cumbias to a classic blues number and an old Mexican ballad. As the clock edged closer to midnight, the middle-aged crowd thinned out, replaced by young men, most of whom, I was told, were musicians. In the middle of a polka called “La Cárcel” (“The Jail”), the band brought the volume down to a whisper, then crescendoed as they approached the chorus, whereupon they flipped the rhythm on its head and dove into a bebop swing line. Castillo’s fingers ran up and down the accordion in a blur. Two men at the bar watched Castillo’s hands, then glanced at each other, laughing with disbelief. After twenty or thirty seconds, the audience looked awed, their eyes widening as the band wound the rhythm back into the polka, culminating with a final bombastic chorus. Whether Jordan would have loved every moment was hardly in doubt. But by the end of the night nobody was asking that question.