He spent years playing with Art Blakey, Lee Morgan and Max Roach, earning praise for his sax’s piercing cry. He’s still composing and turning heads live.Billy Harper grew up in front of an audience. Every Sunday, his family buttoned him into a suit and tie with a freshly starched shirt and drove to Saint Paul African Methodist Episcopal Church in Houston, where his grandfather preached and young Billy sang. “They were having me onstage when I was 3, singing solos,” he said. “The music was getting inside me.” Surrounded by great vocalists, he thought he was going to be a singer, too: “Until I got the horn.”Harper moved to New York in 1966, when he was 23, and began turning heads with the piercing and songful cry of his saxophone. It didn’t take long for him to become a prized collaborator for members of the jazz pantheon like Art Blakey, Max Roach and Lee Morgan. One of the last standing from his generation, Harper, who turns 80 on Tuesday, is still revered in the jazz world as both saxophonist and composer.Earlier this month, he played four nights at Smoke, the Manhattan jazz club, where attendees got a blast of his singular sound, which summons the urgency of John Coltrane and the power of the Black church. A charismatic presence onstage, dressed entirely in black leather, Harper calls his listeners to attention. His improvisations are torrential, dance-like and swinging, spiraling upward to mountaintop pronouncements that can leave listeners in a sweat.“His music is bracing,” said the pianist Francesca Tanksley, who has performed in Harper’s bands since 1983. She credits him with opening doors of inspiration, so that the music “becomes less of a craft and more of an adventure. He’s a man on a mission, he always has been — a knight of sorts.”The drummer Billy Hart, who plays with Harper in the all-star hard bop group the Cookers, said Harper’s music reflects the divine. “I’ve known Harper for 50 years, and we don’t even talk that much,” he said. “I don’t know exactly what he believes, but I can hear it. It’s rhapsodic. He’s praying on the bandstand.”Harper said that music comes to him in his sleep or while walking down the street: “Suddenly I’ll hear a tune in my head, and sometimes I’ll hear a whole choir of voices, singing it.”Scott Rossi for The New York TimesHarper shrugs off praise. “I just want to be a pure musician,” he said, speaking by phone from his apartment in Harlem, where he lives with his wife, the singer Morana Mesic, and their 11-year-old son, Prince. His mission at 80 is the same as when he was 25: “The idea is to make a mark in the creative music world — not anything commercial — just add something to what has already been done by the guys who came before me. If I can just do that, then I’ve done my part. I’m doing it.”He has long flown under the media’s radar, perhaps because his career took off as rock grew dominant in the music industry and independent jazz labels struggled. His debut album, “Capra Black,” recorded 50 years ago with a hotshot band and a choir, is a classic of what’s come to be known as spiritual jazz. Harper has never played anything but spiritual jazz. You can hear it in his stirring tunes, stretching back to the 1970s: “Cry of Hunger,” “The Awakening,” “Trying to Make Heaven My Home.”As a composer, he bears comparison with more famous musicians like Wayne Shorter and McCoy Tyner. Some of his compositions seem to unfold across vast landscapes, majestic and haunting, as if Harper were traveling through epochs of time. “Billy is a griot, a storyteller,” said T.K. Blue, the saxophonist and flutist who performed with Harper for 30 years in bands led by the pianist Randy Weston. “I can hear the history of where he comes from in that music. It’s regal. I hear Africa. I hear Texas. I hear the blues.”Harper spent much of his childhood in Houston’s Third Ward, a historically Black neighborhood filled in those days with blues joints. Walking past a music shop when he was 11, he spotted a shiny tenor saxophone in the window and was intrigued by its complexity — its multitude of buttons and keys. Returning home, he announced that he wanted either a pony or a saxophone for Christmas. (He got the horn.)Harper’s Uncle Earl, an old schoolmate of the bebop trumpeter Kenny Dorham, introduced him to albums by Dorham, Horace Silver and Sonny Rollins. Harper, self-taught, played along with the records and in school marching bands, and soon began sitting in with blues bands around town.By 1961, when Harper arrived at North Texas State University (now the University of North Texas), his playing “had the soul stuff, the feeling,” he said. “But I had to get the technical stuff, and they made me get it together.” Enrolled as a music major, he took his first-ever saxophone lessons and developed a grueling regimen. Holing up in a practice room for 10 or 12 hours at a time, daily, he garnered a reputation: “People thought I was crazy — or that I was going crazy,” he recalled, with a laugh.Harper has recorded 20 or so albums with the quintet, and is planning a new one. He’s been writing songs inspired by his 11-year-old son.Scott Rossi for The New York TimesToward the end of his junior year, Harper won a seat in the school’s prestigious One O’Clock Lab Band, known for its polish and professionalism. It was 1964, and Harper became the first Black student ever accepted into the ensemble: “It was a big thing to get in, though I hadn’t really thought about it back then,” he said. The other musicians “were open and warm, and the band was off the charts. After that, I was ready for anything.”After graduating in 1965, he spent a year or so in Dallas, jamming with big-time saxophonists like James Clay and Claude Johnson, veterans of Ray Charles’s band. Then in 1966, Harper jumped into his black Mustang fastback and drove to Manhattan. His second night in the city, he parked in front of the Five Spot Cafe on St. Marks Place and rushed inside with his horn to hear Thelonious Monk. He forgot to lock the car, and was robbed of nearly everything he owned. That first year in New York was a challenge. He tried sitting in nightly at Slugs’ Saloon, a jazz mecca on the Lower East Side, but rarely got a paid gig.But in 1967, a chance meeting on Broadway with Gil Evans, the composer, arranger and Miles Davis collaborator, led to an invitation to rehearse with Evans’s big band. Harper would become one of its important soloists. Word spread and his résumé grew.Harper — himself an accomplished drummer — spent years playing with the drummer Art Blakey’s Jazz Messengers. He was a member of the trumpeter Lee Morgan’s final band and was at Slugs’ the night Morgan was fatally shot there in 1972. He spent much of the ’70s in a quartet led by the drummer Max Roach, and held the first tenor chair in the Thad Jones-Mel Lewis Orchestra. Its leaders would keep him glued to his seat until the end of a set — at which time, like a pent-up thoroughbred leaving the gate, he would rise to deliver a scarifying blizzard of a blues-drenched solo.His A-list collaborations continued over the decades; since 2010, Harper has recorded half a dozen albums and toured widely with the Cookers while also maintaining his own group, which he described as authentic: “We have a soul-heart-mind connection when we play together,” he said.Typically, members stick with the quintet for years, if not decades, as in the case of Tanksley. To this day, she said, when the band plays one of Harper’s compositions, the musicians seem to enter “a small universe with its own state of being.”Harper has recorded around 20 albums with the quintet, though it’s been a while — the group’s most recent disc, “Blueprints of Jazz Vol. 2,” came out in 2008. His recordings can be as hard to find as they are musically definitive.He plans to make a new album this year and has been composing a set of tunes inspired by his son. He said that music comes to him in his sleep or while walking down the street: “Suddenly I’ll hear a tune in my head, and sometimes I’ll hear a whole choir of voices, singing it. So I run home and write it down, fast.”Not every 80-year-old maintains this level of creativity; playing a tenor saxophone for hours at a time requires a serious degree of physical conditioning. But Harper — who used to jog miles daily and trained as a martial artist — finds that his energy doesn’t flag much.“Inside, I feel 25, maybe 26,” he said.And he’s still turning heads with the singing sound of his saxophone. His friend Hart compares him to the Pied Piper of Hamelin: “People want to hear that sound. Charlie Parker had it. John Coltrane certainly had it. It’s a sound that doesn’t change the notes, it makes the notes, and that’s the sound that Billy has.” More