Ralph Stanley, one of the founding fathers and great originals of American bluegrass music, died on Thursday. He was 89.

His grandson, Nathan, posted on his Facebook page that Ralph Stanley died after a long battle with skin cancer.

“My heart is broken into pieces,” he wrote. “My papaw, my dad, and the greatest man in the world, Dr. Ralph Stanley has went home to be with Jesus just a few minutes ago. He went peacefully in his sleep due to a long, horrible battle with Skin Cancer.”

His publicist, Kirt Webster, also confirmed the news to the Associated Press.

Partnered with his older brother Carter, tenor singer and banjo player Stanley helped develop the “high lonesome” sound of bluegrass, the virtuosic string band music established in the late 1940s by singer-mandolinist Bill Monroe and his dissident sidemen, guitarist Lester Flatt and banjoist Earl Scruggs.

The flinty Stanley always backed away from the “bluegrass” label, however, choosing to associate his highly personalized style with a more venerable type of music.

In “Man of Constant Sorrow,” his 2009 memoir penned with Eddie Dean, he wrote, “If you press me on it, I’ll tell you the same thing I always tell the crowd at a show: ‘[I play] old-time mountain style of what-they-call-bluegrass music.’ It’s a mouthful, I reckon, but it’s about the best I can come up with.”

Initially performing under the sway of Monroe (with whom Carter Stanley later sang in the early ’50s), the Stanley Brothers and their band the Clinch Mountain Boys formulated their own distinctive approach to the bluegrass genre, and developed a memorable original repertoire. They recorded prolifically for Columbia, Mercury and King Records into the ’60s.

Following Carter’s death in 1966, Ralph Stanley struck out on his own, recording a highly prized series of albums for the independent label Rebel Records.

Dr. Stanley — known thusly in the bluegrass community for his honorary doctorate from Tennessee’s Lincoln Memorial University — witnessed a remarkable career resurgence after his music was featured in the Coen brothers’ 2000 film “O Brother, Where Art Thou?” and its blockbuster soundtrack album.

Winner of three Grammy Awards, Stanley was honored with the National Medal of the Arts in 2006.

He was born 18 months after his brother, in Dickenson County, Va., in the Appalachians. He was raised in the Primitive Baptist Church, which favored the close-harmony singing that would feature in his later work. His mother, Lucy, played banjo in the early two-finger “clawhammer” style, and she bought Ralph his first banjo from an aunt for $5.

While his father, Lee, was not a trained musician, he sang at home, and Stanley would later credit him for introducing the brothers to the old-time songs that would appear in their repertoire, most notably “I’m a Man of Constant Sorrow.”

After graduating from high school and serving an Army hitch in occupied Germany, Stanley contemplated enrolling in veterinary school. But instead he decided to join his brother, already a veteran of the string band the Blue Ridge Mountain Boys, in a new unit, the Clinch Mountain Boys. Carter usually took lead vocals, with Ralph contributing high harmonies.

The act — which took its cues from the recent groundbreaking sides recorded for Victor by Bill Monroe’s Blue Grass Boys — garnered attention with their radio performances on WNVA in Norton, Va., and WCYB in Bristol, a town divided by the Virginia-Tennessee border. (Earl Scruggs joined the latter station during the Stanleys’ tenure there, and was undoubtedly instrumental in Ralph’s adoption of Scruggs’ sophisticated “three-finger” banjo style.)

The Stanleys’ 1947-48 recordings for Rich R Tone Records, an independent label in Johnson City, Tenn., included covers of some of Monroe’s early sides and Carter Stanley originals like the chilling murder ballad “Little Glass of Wine.”

The records put the brothers on the map, and in 1949 the Clinch Mountain Boys were signed to Columbia Records. Bill Monroe, who was a star on the label’s roster, viewed the Stanleys as formidable competition, and soon exited the label in a huff for Decca.

The Stanley Brothers’ 1949-50 Columbia sides showed their swiftly developed mastery of the bluegrass style, featuring both secular and gospel songs executed with high energy and intensity. A 1950 session marked the recorded debut of “I’m a Man of Constant Sorrow,” with a lead vocal by Ralph.

The brothers were briefly separated when Carter signed on with a forgiving Monroe for a brief stint as lead singer. The bluegrass elder even offered to hire both brothers and feature them in the Blue Grass Boys with joint billing, but the Stanleys regrouped for a final session for Columbia in 1952.

After a short return to Rich R Tone and regional radio work, the brothers were inked by Mercury Records, where Flatt & Scruggs had recorded their first high-voltage sides. The Stanleys’ 1953-58 recordings for the label were works of rare beauty and power, and even exhibited a rare departure from their tradition-based sound, on the steel guitar-inflected “If That’s the Way You Feel.”

The pair’s longest label association was with Cincinnati’s King Records, which released their material from 1958-66, a period that also saw the Stanleys attain their highest profile as live performers at folk and bluegrass festivals. Their tenure with the label found them recording in a variety of styles, essaying bluegrass, folk and gospel and even straying occasionally into pop — they cut a surprising cover of label mate Hank Ballard’s R&B hit “Finger Poppin’ Time.”

By the mid-’60s, Carter Stanley’s escalating alcoholism had taken a toll on his abilities as a performer, and he died from cirrhosis of the liver on Dec. 1, 1966. Though Ralph contemplated giving up music, he decided to front the Clinch Mountain Boys as a soloist.

He wrote in his memoir, “I could hear Carter saying, ‘Little brother, don’t let me down.’ I had to go back and do my best, the way he had done for all those years.”

Stanley went on to record solo for King, but he had his most rewarding association with Rebel, an indie label operated by bluegrass enthusiast Dick Freeland out of the basement of his Washington, D.C., home. His recordings for the company stretched from 1971 into the new millennium.

From the early ’70s on, the Clinch Mountain Boys became a formidable breeding ground for top bluegrass talent. One of Stanley’s early stars was lead vocalist Roy Lee Centers, who was tragically shot to death after an argument at a party in 1974. Guitarist Larry Sparks went on to an award-winning solo career.

Stanley’s greatest discoveries were future country stars Ricky Skaggs and Keith Whitley. The duo, then performing together in the Lonesome Mountain Boys, were asked to stretch out their opening set at a show in Fort Gay, W. Va., after Stanley failed to arrive on time. Impressed, the bandleader hired the teenagers, who contributed to the stunning 1971 gospel album “Cry From the Cross” and the secular set “Something Old – Something New.”

Stanley released dozens of albums through Rebel and Freeland’s eponymous latter-day label. He attracted the greatest attention with 1991’s “Saturday Night and Sunday Morning,” an all-star two-disc set split between secular and sacred material. Guests included Bill Monroe, Jimmy Martin, George Jones, Emmylou Harris, Vince Gill, Dwight Yoakam, Patty Loveless, Alison Krauss and former band members Skaggs and Sparks.

His late-career breakthrough to international stardom came when T Bone Burnett enlisted him for the country-steeped soundtrack of the Coens’ period comedy “O Brother, Where Art Thou?” The producer was seeking a cover of “O Death” in the manner of early hillbilly performer Dock Boggs’ banjo-accompanied version, but Stanley convinced Burnett to let him perform it a cappella.

Voiced in the film by a hooded Klansman, “O Death” became one of the highlights of the Mercury soundtrack album, which became a must-have roots music set that sold nearly 8 million copies in the U.S. The collection served as a virtual homage to the Stanley Brothers: It contained multiple versions of “I Am a Man of Constant Sorrow” (as performed by Dan Tyminski of Alison Krauss’ band Union Station), and closed with the brothers’ original 1955 version of “Angel Band.”

In 2002 — 55 years after the start of his recording career — Stanley received his first Grammy Award for male country vocal performance, for “O Death.” He also shared in the album of the year Grammy won by the “O Brother, Where Art Thou?” soundtrack. (He received a third Grammy in 2003 for “Lost in the Lonesome Pines,” named best bluegrass album.)

No longer a niche genre luminary, septuagenarian Stanley became an international star in the film’s wake. He was featured in the national “Down From the Mountain” tour and a subsequent documentary directed by D.A. Pennebaker, Chris Hegedus and Nick Doob. He also released his first major-label records in nearly half a century, cutting two acoustic-based collections of traditional material for Burnett’s Columbia-distributed DMZ imprint.

Though he ceded banjo playing to his band mates, Stanley remained a trouper into his 80s on tour with the Clinch Mountain Boys. He was frequently co-billed with his grandson, gospel singer Nathan.

His survivors also include his wife, Jimmi; son; Ralph II; and daughter, Jeanie.