The magazine Bluegrass Today reported that Crowe, who retired in 2019, had chronic obstructive pulmonary disease.

As the leader of the Kentucky Mountain Boys, later rebranded as the New South, Crowe was among the first musicians to adapt rock, urban folk and even rhythm-and-blues to the bluegrass repertoire in the late 1960s. Often dubbed “newgrass,” it was an approach he shared with other contemporary groups such as the Washington, D.C.-based Country Gentlemen and Seldom Scene.

Del McCoury, center; Bobby Osborne, left; and J. D. Crowe, right; perform at the International Bluegrass Music Association Awards show in 2012, in Nashville, Tenn. Mark Humphrey/Associated Press

Widely known among fellow musicians for his tone and nearly flawless meter on the banjo, Crowe led bands that were an incubator of talent. The classic mid-1970s edition of the New South featured future country star Ricky Skaggs on mandolin and fiddle, guitarist Tony Rice on lead vocals and a then-19-year-old dobro prodigy, Jerry “Flex” Douglas. The band developed a rare cohesion through a four-set-a-night, six-night-a-week gig at the Lexington, Ky., Holiday Inn.

“It was work, work, work,” Skaggs recalled in an interview. “It would be four shows a night for 45 or 50 minutes – we had to have a lot of material … I remember woodshedding a bunch, learning 30 or 40 songs to do every night.”

Their 1975 album, eponymously titled “The New South” but better known among bluegrass fans by its catalogue number, “0044,” was remarkably eclectic. Crowe’s boisterous instrumentals and Rice’s mellow interpretations of Gordon Lightfoot songs shared the grooves with a wild rendition of Fats Domino’s “I’m Walkin’ ” and a vocal trio version of Gram Parsons’s “Sin City.”

“All we did was we took tunes nobody was doing,” Crowe recalled in the liner notes to a 2011 reissue CD, “and it was like they were new tunes as far as the bluegrass genre was concerned.”

Skaggs, already a veteran musician when he joined the band at 21, called Crowe “a man of few words who led by example.”

“His playing was so intricate and his timing was like a watch ticking – especially when he did an intro,” Skaggs said. “He wasn’t wavery on his intros. We always knew where the one [downbeat] was. Timing is something I learned from him.”

The young band dressed casually and wore their hair over their collars, prompting the father of bluegrass, Bill Monroe, to joke that they looked a herd of Shetland ponies.

Although Crowe’s bands went through many personnel changes, later editions of the New South were equally stellar and included such performers as lead singer Keith Whitley, who dominated the country charts in the 1980s, and the fleet-fingered mandolinist Jimmy Gaudreau. Often straddling the fence between newgrass and country rock, Crowe added steel guitar and drums to his lineup during Whitley’s tenure in the band.

Although he would freely admit to being inspired by the classic three-fingered banjo styles of Earl Scruggs and Sonny Osborne, Crowe carried many blues and rock ‘n’ roll licks in his toolbox and enjoyed blurring musical boundaries. He derisively dismissed hidebound genre purists who took issue with the group’s versatility.

In 1981, Crowe recorded “The Bluegrass Album,” which featured interpretations of the traditional bluegrass repertoire with an all-star unit that included Rice, mandolinist Doyle Lawson (another veteran of Crowe’s band) and fiddlers Vassar Clements and Bobby Hicks. Crowe and Rice went on to tour and recorded five more albums as the Bluegrass Album Band. Grammy-winning singer and fiddler Alison Krauss reportedly kept a framed copy of their first album’s cover in her home.

Crowe and Rice brought the music of Monroe and Flatt and Earl Scruggs to a new generation at a time when many of the original recordings were available only as prohibitively expensive imported reissues.

“When the Album Band did those recordings,” Crowe told Banjo Newsletter in 2019, “we didn’t try to play exactly like them because we knew we couldn’t! They’ve already done it the best it’ll ever be done. What we did is play a tribute to them for how we learned, this is how we feel playing those songs.”

James Dee Crowe was born Aug. 27, 1937, in Lexington, Ky. His parents were farmers. He took up guitar as a boy, inspired by Ernest Tubb’s guitarist BillyByrd. He switched to banjo at age 12 after seeing Flatt and Scruggs perform an impromptu audition for the Lexington radio show, “The Kentucky Mountain Barn Dance.” By 18, he was working professionally with singer Mac Wiseman.

In 1956, Crowe joined Jimmy Martin and the Sunny Mountain Boys, regulars on the “Louisiana Hayride” in Shreveport and the “Wheeling Jamboree” radio and TV programs. With Martin, he played on such hits as “You Don’t Know My Mind,” “Hold What You Got” and his own instrumental feature, “Bear Tracks,” all from 1960. Desiring a respite from constant road work, he started the Kentucky Mountain Boys in Lexington in 1961.

Crowe received a 1983 Grammy Award in the country instrumental category for his song “Fireball.” He received numerous honors from bluegrass music groups, including a lifetime achievement award from the International Bluegrass Music Association in 2003. The annual the J.D. Crowe Bluegrass Festival in Wilmore, Ky. is named for him.

Survivors include his wife of 48 years, the former Sheryl Moore; two children; and a granddaughter.

Crowe was often asked about how to get the best sound from a banjo.

“You have to play up to the point to where you [draw] the tone out of your instrument,” he said 2010. “But once you start playing too hard – I’ve caught myself and I know immediately when I do it because the tone starts leaving or it doesn’t blend with the other instruments.”

He added, “You have to know where that point is in that instrument. And that’s where you want to keep it.”