In some ways it seems destined that Bela Fleck would grow up to become one of the world's most stylistically diverse and accomplished banjo players. His parents named him Bela Anton Leos Fleck, after the Eastern European classical composers Bela Bartok, Anton Dvorak and Leos Janacek. Spoken together, his first and last names have a mellifluous yet puckish sound not unlike the quality of banjo notes.

But what really transformed Fleck into the musician nominated in more Grammy Award categories than anyone in history is his confidence and curiosity, be it the time as a boy when he decided he wanted to play banjo like Earl Scruggs on the "Beverly Hillbillies" theme song, or the time three years ago when he climbed onstage with banjo in hand at a jam session held by jazz pianist Marcus Roberts in Savannah, Ga.

"We just started jamming in open G and worked in some blues, but complex jazz blues, going wherever you want to go," Fleck recalled. "Usually in a jam, one person solos and then the other solos, but almost immediately we started playing with each other. I love to echo back what my partner has just played, only a measure or two later in counterpoint, while winding my own line, and we just naturally fell into that."

Fleck subsequently went to see Roberts in Tallahassee, Fla., where the pianist lives and teaches at Florida State University. He sat in with the members of Roberts' trio, drummer Jason Marsalis and bassist Rodney Jordan, and the chemistry deepened. This June, the foursome released an album aptly titled "Across the Imaginary Divide," with music written specifically for their collaboration -- six songs apiece from Roberts and Fleck. Now they are exploring the relationship further with an extensive tour that stops Wednesday and Thursday at the Dakota Jazz Club in Minneapolis.

"I've got to say it is fun music to play -- and it changes every time we play it," said Roberts by phone from Florida. "I guarantee what you hear in Minneapolis isn't what's on the record, although they are all the same songs. We're taking it into jazz areas and shaking it up."

The tour is Fleck's latest rebuttal to the carping of jazz purists who contend that his pair of Grammys for best contemporary jazz album -- for "Outbound" in 2000 and "The Hidden Land" in 2006, both recorded with his bluegrass-jazz hybrid band the Flecktones -- lacked the rigorous spontaneity and improvisation that is the lifeblood of the genre. An album and tour performing duets with eminent jazz pianist Chick Corea blunted that argument, but he takes it a step further with Roberts, a former bandmate of Wynton Marsalis, whose jazz bona fides are beyond reproach.

"The challenging thing about Marcus is that he gets very uncomfortable playing something the same way," Fleck said. "With the Flecktones, the tempo would be pretty similar and the improvisations start to solidify. But Marcus will play fast one day and then the next day go at half the tempo. He wants me to tap into what he calls my unconscious self so I can't have worked on something to be ready for that night; I have to be spontaneous and respond to whatever structure it is we're playing."

Roberts is impressed. Noting the tightness of his trio -- he has played with Jason Marsalis for 18 years -- he admitted that "it kind of shocked me that from the beginning Bela wanted to dig in and not have a casual role, not be a trio plus special guest, but really explore the philosophy and language of what we do. He was the one who wanted to write music just for this project. He is serious about how he plays and we admire him for it. At the same time we are learning the different approaches to rhythm that he has, so it is a true collaboration.

"There is a lot of syncopation in both bluegrass and ragtime," noted Roberts, who has become renowned for his comprehensive yet progressive approach to ragtime. "A lot of the melodies and scales are similar. Maybe that's why we hit it off so well, because we can tell that the roots and flavor and connection are there."

Fleck expected no less. "I look for partnerships with people who have info I don't have access to," he said. "I wanted to learn more about jazz from these three people I respect so deeply. And over time that's what has happened. The way we went back and forth on the title song to 'Across the Imaginary Divide,' everybody was pretty thrilled about it in the studio. But with these months of playing together on the road, those exchanges have just gone through the roof."