It starts with a fluttering, circling, almost improv part. Then a second part rides in, a bit more insistent, clawhammer-style, carving a melody with its strings. So familiar, and yet. Then a woman’s voice joins in, a sweet powdery sound but grounded in something earthy and raw, and rising into a variation on the traditional I’ve Been Working On the Railroad. It is obvious that Abigail Washburn and Béla Fleck are going to validate and recast everything known about modern banjo.

“The piece was the grand design,” says Ms. Washburn, about the pair’s self-titled debut. “Just two banjos and a vocal, nothing more. Let everything else fall away.”

“When you’re up close to a banjo and you can capture it, there’s a magic to it,” adds Mr. Fleck, warming to the topic of the unlikely creation of their record. “The beauty gets covered up in more conventional recordings. A guitar will soak up a lot of the frequencies. There are a lot of the same strings, so the harmonics are beautiful, but the magic gets lost.”

Mr. Fleck is one of the founders of the progressive bluegrass supergroup/band New Grass Revival. He also founded the Flecktones as a jazz/worldmusic/whatever fits collaborative. He has won 15 Grammy awards including Best Pop Instrumental, Contemporary Jazz, Classical Crossover, Country Instrumental, Contemporary World Music and the overall Instrumental Composition.

And on Wednesday, April 15, Béla Fleck and Abigail Washburn will be coming to the Vineyard to play at the Performing Arts Center at the regional high school. The concert is a benefit for Island Collaborative, a new nonprofit that focuses on collaboration between the arts, business, government and schools.

While Mr. Fleck’s musical journey could be considered relatively direct, Ms. Washburn’s route was much more unlikely. As a student in Evanston, Ill., she never made the “good choir.” She graduated from law school, worked in China, served as an activist in Vermont, and along the way almost inadvertently began playing with Uncle Earle, the second incarnation of old-timey, bluegrass bands. She caught a record deal with Nettwerk, which released Song of the Traveling Daughter in 2005. And for the past decade, she has built a following with her traditional Appalachian, folk and songwriter etchings.

And then there’s the fairy tale.

When Mr. Fleck first heard Ms. Washburn’s songs, the music so charged him he was pulled over for speeding. He would go on to produce Traveling Daughter. Later, as part of Ms. Washburn’s cultural exchange with China, he toured as part of her Sparrow Quartet, along with noted fiddler Cassey Driessen and cellist Ben Sollee.

“It’s funny,” Ms. Washburn says of her musical journey. “The first song I wrote in English, the second in Chinese. I was very practical, and I figured I wasn’t going to make a living off being a bad singer, so I had to go off to China.”

While Ms. Washburn resisted the notion of a straight collaboration with Mr. Fleck, the inevitable has a way of happening.

“I had some success, but my ego had trouble catching up with the responsibility,” Ms. Washburn explains. “I was learning to play, having things come together, but I didn’t feel equipped to go on the road and play with Béla. I wanted to have something to offer — and it took me 10 years.”

“I always felt that once they heard her play,” Mr. Fleck says, “they’d see us, they’d understand. They’d see and hear what I did. And it’s all developed over time.”

Over time, and love, and life and a baby named Juno.

Both musicians forged their careers through touring and a bit of wanderlust, and they understand that music must be played live to truly find its way. Having fallen in love, married and had a child, they realized how important it would be for them as a family to merge their musical realities. It also colors their music.

“Being around a kid really teaches you about simplicity,” Mr. Fleck offers.

“Everything’s a whole new experience,” adds Ms. Washburn. “It changes how you see things.”

In that wide-open curiosity, both partners met on familiar ground for this album. Recording with intention, it was the willingness to go new places that truly tapped into something new.

“When you’re learning new music, you have to be willing to sound bad,” Mr. Fleck begins. “Abby was so game for trying things. Whatcha Gonna Do? was like that. New South Africa, too. It was a lesson I took from Edgar Meyer teaching me Bach, because I don’t read music. Be patient.”

“It took a new kind of singing,” adds Ms. Washburn. “A lot of words squeezed together fast and high in my register. It wasn’t natural, but I found it.”

“Yes, she tried and it went beautifully,” confirms Mr. Fleck.

The gentleness of their collaboration informs the music’s intimacy, and draws listeners into variations on Bartok, children’s music, the recast bluegrass of What Are They Doing In Heaven Today and the folk standard And Am I Born To Die?

It is knowing and trusting that lets well-loved songs be recast, and letting ethereal notions ground roots music. For the pair, 10 years into a creative partnership that’s teamed for pickin’ parties, charity events and festivals, this is the moment where all of their love, talent and experience come together live and on the record.

“Instinct is a huge piece of everything,” Ms. Washburn relates. “I don’t think about the music I make. It comes from a different place than the intellect. It’s knowing without knowing — and you know when it’s right.”

“You don’t think, I wanna play this like this,” Mr. Fleck continues. “It’s intuitive. We’re always looking for magic, that’s what you want. It’s magic, and it’s not mathematics.”

It’s hard to tell which is stronger — their love or their artistry. Each knows the other so well, understands the other’s talents and how to embellish them. Laughing, Ms. Washburn concedes, “You hear both of our personalities. We did a pretty job of capturing a guy who’s complicated, into varied rhythmic things and breaking new ground, against a woman who prizes very clear and simple music — and somehow managing to balance both.”

“Music has to have several layers,” Mr. Fleck explains. “The top is the sugary crust that makes you want to crumble and have some more. The lower layers have surprises, more depth, more flavors. I think both of us have that in different ways. Here, we have it together.”

An Evening with Béla Fleck and Abigail Washburn begins at 6 p.m. on Wednesday, April 15, at the Performing Arts Center at the regional high school. Tickets are $35 in advance and $45 at the door. Contact 800-838-3006 for tickets. The event is a benefit for Island Collaborative, a new non-profit organization working to facilitate collaboration between Island civic organizations, local government, schools, businesses, nonprofits and individuals.