Some 60 years ago, Bob French and his wife, Grace, were playing guitar and singing with the Rainbow Valley Boys, performing country music nearly every night while traveling through the region and raising their children.

Then one evening in the mid-1950s they took a break from the 10-gallon hat crowd and rode a bus into Boston to see a bluegrass band at the Mohawk Ranch club in the Combat Zone. Mr. French was amazed by the banjo playing of a skinny 17-year-old and moved close to watch his fingers fly.

“I told my wife that night, ‘I’m going to learn to play one of those,’ ’’ he told Salty Dog magazine in 1977. “She said, ‘You’re foolish.’ ’’

During the decades that followed, Mr. French and his wife helped popularize bluegrass in New England, and his Earl Scruggs-style banjo picking was a draw from their Pawtucket, R.I., radio show to the home they found in Cambridge, Maine, after they decided that Boston’s suburbs were too crowded.

Mr. French, who at various times shared the stage with the likes of Doc Watson, Dolly Parton, and Janis Joplin, died Aug. 20 in Central Maine Medical Center in Lewiston of complications from surgery. He was 86 and spent nearly half his life in West Acton before living in Concord, Shirley, and Maine.

“We always started off every show with a brief history of what the music was all about,’’ he told Salty Dog. “I’d have to walk out on stage and introduce the audience to the music first, then we’d bring the band out and start playing.’’

Persuading New England audiences that were accustomed to country music to accept bluegrass often tested the couple’s diplomatic skills.

“Bob and I loved bluegrass, but to get the audience to really listen and feel the warmth of the music we had to play old country tunes and intermingle them with bluegrass,’’ Grace said in an interview for the 2013 book “Pretty Good for a Girl: Women in Bluegrass,’’ by Murphy Hicks Henry.

As performers, they also faced constant challenges that included holding down day jobs to supplement their music wages and Grace needing to take occasional breaks from touring to spend more time with their children. Their bands, meanwhile, featured a changing lineup of musicians.

“The trouble with bands, there’s good bands and bad bands, but bands don’t stay together,’’ Mr. French told Salty Dog. “They come and they go. Musicians are a restless breed. You get into something for a while and you want to experiment; you’re looking for new material and the only way to get it is to go with other groups, so bands come and they go.’’

Robert George French Sr. grew up in West Acton, where his parents had settled after emigrating from Nova Scotia and Newfoundland. His father, James, was a logger turned driver of logging trucks. His mother, the former Ada Mae Wamboldt, mostly raised the children.

In a family that ran short of beds, Mr. French was the youngest of 11. “He had to sleep with the dog next to the woodstove at night,’’ said his daughter Jeanne of Singapore. “They had a pallet there and that was the warmest place to sleep.’’

The family was so expansive that Mr. French was 30 years younger than his oldest brother. “He had a couple of nieces and nephews older than he was, calling him Uncle Bob when he was crawling around on the floor,’’ his daughter said.

As a boy, he listened to the Grand Ole Opry and the National Barn Dance on the radio and also drew inspiration from musicians in his family, including a brother who played harmonica in a band called Pick, Windy, and Stretch.

“When I got into my middle teens, my sister got into a country band,’’ he told Salty Dog. “They wore 10-gallon hats, cowboy boots, spurs, guns, and all.’’

Mr. French met Grace Haley on a blind date when both were 16 and she was singing in a country band. She went on to attend college for a year and work as a model before marrying Mr. French in 1950, two years after they finished high school.

“He had two loves, the banjo and my mother. He was so desperately in love with her,’’ their daughter Jeanne said. In later years, sometimes Mr. French and his wife would be in a room together, “and he would sit here and look at the clock and then look at her and say, ‘I love you at 4:15 and 20 seconds,’ ’’ Jeanne recalled in an interview from the family’s Cambridge, Maine, home.

Though Mr. French turned down tours that would have taken him too far from home and his day job to support the family, he was devoted to the banjo. Along with clubs and concerts, he performed on the former AM stations WPAW in Pawtucket and WPEP in Taunton — sometimes on the same day, morning and afternoon — and on Clyde Joy’s WMUR-TV show in Manchester, N.H.

Mr. French told Salty Dog he was proud he acquired his banjo abilities long before instructional material for the instrument was easily available. He did so by practicing endlessly.

“One thing about Pop’s playing at home: His practicing the banjo in the kitchen was like reveille every morning when we were growing up,’’ Jeanne, who is also a musician, noted in an e-mail, adding that the instrument “was never far from Pop’s chair. We learned to sleep through it all hours of the day or night.’’

Sometimes lost among the praise fans offered for Mr. French’s banjo playing was that he also was an adept vocalist.

“He could go from basso profondo all the way up to tenor,’’ Jeanne said, “and he had a tone that was like chocolate — very, very smooth.’’

Mr. French’s son, Robert Jr., died two years ago. In addition to his wife and daughter, Mr. French leaves another daughter, Mary Helen Bentham of The Hague; a son, John of Nashua; eight grandchildren; and nine great-grandchildren.

The family is planning a private memorial gathering.

A generous musician, Mr. French gladly showed aspiring banjo players how to master a fancy run on the instrument, and would listen and offer guidance until his newfound pupil got it right.

He also spent his career trying to persuade writers — often fruitlessly — to give Grace equal billing in any piece about their music because they shared the stage as musical partners.

“My father would be the first to say, ‘I never could have done it without her,’ ’’ Jeanne said, “and he would get upset when people would write articles about him and not mention her.’’

Bryan Marquard can be reached at bryan.marquard@globe.com.