Emmylou Harris once characterized Bill Monroe as the first rock ’n’ roller, a description that, on the surface, might surprise people. After all, Monroe played mandolin in a string band. He put his band in matching dress suits and maintained a rule about wearing short hair and no facial hair. He wrote songs about old-time religion, about parents and community, about his rural Kentucky mountain home, about the difference between right and wrong and good and evil. He said “Yes, ma’am” and “Yes, sir,” even to close acquaintances.

These are hardly traits associated with rock music, but Harris wasn’t talking about character or demeanor. She was referring to the forceful rhythmic power and intricate musical progressions Monroe introduced to country music. As Harris explained it, “He took a lot of pieces that were floating around and put the fire in them.”

That he did: Monroe, who died Sept. 9, just a few days prior to his 85th birthday, created a genre of music by tearing into his instrument with a passion previously lacking in folk, country, blues, gospel, or rural mountain music. When Sun Records put out Elvis’ landmark first single in 1954, the A-side featured a speeded-up blues song, Arthur Crudup’s “That’s All Right, Mama”; the flip side contained a similarly electrified take on Monroe’s “Blue Moon of Kentucky.” Another Memphis rockabilly singer, Charlie Feathers, put it this way: “Bill Monroe’s music and colored artists’ music is what caused rock ’n’ roll.”

But Monroe never referred to himself as anything but the Father of Bluegrass. As has been stated repeatedly since his death, Monroe is the only man in history who can rightfully assume sole responsibility for creating a style of music. Asked by researcher Charles Wolfe how he felt to be designated as the father of a musical style, Monroe replied, “Well, I don’t mind that. That’s really the truth, you know.”

Other musical styles were slowly and simultaneously developed by many performers. But Monroe created a legacy all his own, a dignified and hard-to-master music that has maintained a rare kind of integrity. Until the end, however, the music’s loftiest master will always be Monroe. He not only invented it; his music holds up as its highest measure of quality. He’s not just a bluegrass patriarch—he’s its once and future king.

In TV news bites in the days following Monroe’s death, reporters from each of Nashville’s three hometown networks stood in front of the Ryman, saying that Monroe’s career ended as it began, with a memorial service inside the hallowed halls of the former home of the Grand Ole Opry. That’s far from true, of course. Monroe had been touring and recording for several years before he set foot in the Ryman; he’d already been a star performer at radio stations in other cities before arriving in Nashville in 1939.

His career began in 1932 in Northwest Indiana, where he had moved at age 17 after the death of his caretaker, uncle Pendleton Vandiver. He joined his brothers Charlie and Birch as factory workers at an oil refinery in the town of Hammond. Shortly afterward, the brothers were hired as square dancers by the WLS National Barn Dance in Chicago. Two years later, as the Monroe Brothers, they got a job performing daily on a radio station in Hammond. They later moved to the bigger WJKS—“Where Joy Kills Sorrow”—in nearby Gary.

By 1935, the brothers had gained backing from a commercial sponsor, Crazy Water Crystals, a popular tonic and laxative. They moved from station to station through the Midwest before finding their greatest success in the Carolinas. RCA Victor tracked them down in Raleigh and signed them to a recording contract. The Monroes recorded 60 songs for Bluebird, RCA’s discount label, over the next two years.

Bill broke off from his brothers in 1937 following a dispute with his brother Charlie. He formed his own band and called it The Bluegrass Boys, after his home state. To distinguish himself, he took the Monroe Brothers’ blend of mountain string music and gospel-style harmony and speeded up the mandolin and fiddle parts. And in an attempt to capture the sound of Scotch bagpipers, he added intricate, difficult-to-play rhythms and counter-rhythms, placing high-pitched tones over chords drawn from Southern blues and gospel music. “I wanted to play music they could dance to,” Monroe once said.

Eventually, other musicians began emulating this forceful string music, especially after the mid-1940s, when Earl Scruggs joined the Bluegrass Boys. He added a speedy and precise three-finger style of banjo picking that matched the furious bluster of Monroe’s mandolin. At some point—and no researcher has been able to pinpoint exactly how or when—this music started being called bluegrass. More than likely, it came from the mouths of acolytes who formed bands mimicking the exciting, exacting style. As these followers began describing what they were playing, they’d reply, “We play the music of the Bluegrass Boys.” Eventually, they just started calling it bluegrass music.

From the start, Monroe emphasized dignity and integrity in his music and his band. Unlike other acts, he refused to play up the rube element of rural life. Most country bands had at least one comic in the band; not the Bluegrass Boys. They maintained the pose of serious musicians, taking on a cast more familiar to that of classical orchestras or elegant jazz bands.

The Bluegrass Boys worked long hours for low wages, and they traveled incredible distances crammed four or five to an automobile, complete with instruments and luggage. Still, it’s a unique badge of honor to have been among their ranks. Monroe’s band spawned many stars and even more respected instrumentalists. These included Flatt & Scruggs, of course, who performed in the most highly regarded version of the Bluegrass Boys in 1946-47; their first recordings took place on Sept. 16, exactly 50 years ago this week. Monroe’s banjoists included David “Stringbean” Akeman, Sonny Osborne, Hubert Davis, Bill Keith, and Curtis McPeake; the guitarists included Clyde Moody, Mac Wiseman, Jimmy Martin, Carter Stanley, Del McCoury, Peter Rowan, and Doug Green; the fiddlers included Chubby Wise, Vassar Clements, Buddy Spicher, Gordon Terry, Bobby Hicks, Charlie Cline, Kenny Baker, Richard Greene, and Byron Berline.

Monroe wasn’t easy on band members, however. He challenged them onstage with surprises, and he expected them to challenge him musically while never stepping beyond the boundaries he set for them. Sonny Osborne was 14 when Monroe hired him in 1952, and he compared the experience to going to work for God. He had never met Monroe when he was called to fill the position. He was simply told to arrive in Nashville in time for a Grand Ole Opry performance, which he did. Monroe never came over to say hello, shake his hand, or welcome him in any manner. Osborne was told to dress for the show and get onstage at the appropriate time. As they stood waiting for their cue, Monroe never even looked at him. At the appropriate time, the bandleader leaned into the microphone and announced that they would now play “Rawhide”—one of the fastest and most intricate instrumentals in his repertoire. Osborne was expected to jump in and keep up.

Monroe maintained other peculiarities about his band. He had heard Bill Keith play and sent Kenny Baker to offer him a job. Once hired, he asked the Boston native what his name was. Keith told him, and Monroe then asked, “Well, what do they call you?” Keith said, “Bill.” Monroe said, “What’s your real name? Your full name?” The banjoist said, “William Bradford Keith.” Monroe retorted, “I’ll call you Brad,” and from then on introduced him as “Brad Keith.” There was to be only one Bill in the Bluegrass Boys.

At the same time, Monroe also nurtured his musicians. He’d take time with each new recruit, spending hours teaching them the intricate style he wanted them to master. In doing so, he set a standard that has made bluegrass musicians uniformly respected for their high-caliber instrumental ability. “He could be sour, but he was a great teacher,” Baker once said of Monroe.

He was as single-minded as a man could be. He could be stern and silent one moment, animated and talkative the next. He was independent and introspective, but his thoughts always returned to the music; he cared about little else. Married and divorced twice, he gave little time to relationships. He spent most of his time off the road picking on his mandolin or working on his ranch outside of Nashville, where he depended on mules and horses, rather than tractors, to clear land or till fields. An active man, he kept healthy and strong through hands-on labor.

That strength kept him going. He once underwent emergency heart surgery in Nova Scotia; three hours after it was over, he was pushed onstage in a wheelchair to sing and play at a bluegrass festival. After another hospitalization in Nashville, he rested for 10 days before playing three days straight at a bluegrass festival, then getting on a bus for an overnight trip to a state fair, where he performed for another six consecutive days. He always said that only death would stop him from playing bluegrass music for the people.

An old bluegrass joke tells of a picker’s entrance into heaven. The musician is welcomed by several heroes, including Lester Flatt and Carter Stanley. In the distance, way up on high, a dignified man in a white hat stands tall and erect, playing a mandolin and singing “Blue Moon of Kentucky.” Since Monroe was still among the living, the newcomer turns to St. Peter with a surprised look. St. Peter replies, “Oh, that’s God. He just thinks he’s Bill Monroe.”

Now God can finally learn how to play the song as the master would have it.